"I have hardly unpacked my suitcase," she admits, before again sending her suits off to the dry cleaners. "I am normally a tidy, orderly soul. I am longing to see my own house." It is hardly surprising that Jowell has been put in charge of winning support for London's bid. If any member of the Cabinet is good at "being nice to people", it is she.
Jowell's world tour in search of support for London has not been without surprises. In Qatar last week, a devout Muslim woman leant over at a lunch and, in confidential tones, told her: "Every day I pray that Michael Owen and Ronaldo will play on the same side for Manchester United."
"This was a woman shrouded in black who is an absolutely passionate Man Utd fan," Jowell said.
The minister is an Arsenal fan and has at times found herself at Highbury, waiting in line to buy the latest club shirts for her sons.
"I was always the mother at the top of the queue for the new Arsenal kit, because both my kids were Arsenal fans," she says. "The merchandising is very expensive but you will be very glad to hear that it is not for ministers to set those prices - not even a Secretary of State bidding for the Olympics. That is for the competition authorities."
Officially, Tessa Jowell is Secretary of State for Culture, Media and Sport. But right now she is firmly focused on the last element of her job description. On Wednesday in Singapore she will discover whether, after three years of effort and £30m, London has succeeded in defeating Paris for the ultimate prize in the international sporting calendar.
As the 2012 Olympic bid enters its final 36 hours she is certain that there is "everything to play for". With only Paris to beat, Jowell is genuinely convinced the "momentum" is with London.
"Honestly," she says. "I could not be more cautious and less complacent. But as a nation that loves sport we can hold our heads high."
To add a final boost to the British effort, Tony Blair arrived in Singapore with his wife Cherie yesterday. Their presence, particularly on the eve of the G8 summit, and just as the UK takes over the presidency of the EU, is a huge boost to London's hopes according to Jowell - she says members of the IOC "are gagging to meet them".
She adds: "It is impossible to say how positive [and] enthusiastic IOC members are about Tony and also Cherie."
Jowell throws up her arms in disbelief at the suggestion that the Prime Minister's presence could be a hindrance rather than a help in some quarters, because of global opposition to the Iraq war.
"Oh my goodness!" she exclaims, incredulously. "They are arguably the greatest asset we have." Jowell is an unabashed Tony Blair fan and looks shocked when asked exactly why the Blairs are the Olympic bid's greatest asset "Why?" she exclaims. "Because Tony is a world leader."
Jowell says the London bid team "will be making sure that as many members of the IOC as want to talk to the Prime Minister, Cherie, to me, Richard [Caborn, the Sports Minister] or any member of the bid team will be able to meet us and talk to us about our bid."
An estimated 20 per cent of the 115-strong IOC committee are still undecided, according to UK calculations, but Team London may still have to deploy every ounce of their savoir-faire to see off the Parisians. To win those crucial swing votes, Jowell says she will make herself available to any IOC member wanting to talk about the Olympics - even if she is summoned from her hotel room to the bar at 3am. Surely this is pushing dedication too far?
"I am available for any meeting with any IOC delegate who wants to talk about the bid," she says. She adds, with a flicker of a smile: "And all the discussions will be strictly within the very clear rules established by the ethics committee of the IOC."
Jowell says the London bid has no holes to plug in terms of transport, housing, sporting facilities, security or planning permission. "On technical grounds all bases are covered," she says. The task now is to demonstrate to each and every member of the IOC that London has the passion as well as the expertise.
"What we now have to show [is that] we can give the IOC and the Olympic movement the best games ever; that we are absolutely passionate about it; that we are hungry to have this honour bestowed on us. And the whole country is behind it, and the whole Government is behind it."
London's final presentation is expected to stress the public and political support in Britain for the Games, in addition to the stable political climate here.
"This is a contest and we will not stop fighting this contest until the moment the door shuts and the IOC members start voting," she says. "There is a palpable sense of momentum with the London bid."
To win, London needs to win over the second-choice votes of council members planning to vote first for New York or Madrid, cities expected to be knocked out in the first round. To help London's case an entire "smarmy army" of sporting and political celebrities has flown to Singapore to give it the edge over Paris. The Government insists the London bid will not be too glitzy. But it has nevertheless engaged the services of David Beckham, Michael Grade (the chairman of the BBC), Sven Goran Eriksson and Daley Thompson to make its case. At Singapore's luxurious Swiss Hotel the celebrities will appear alongside the Prime Minister.
Victoria Beckham will be accompanying the England captain and the two are expected to hold their wedding anniversary celebration there. Will Jowell be popping in?
"No, absolutely not!" she says, her eyes wide in horror. "That is an entirely private event. No, I will be doing nothing in Singapore except with members of the IOC who would like to talk to me."
Delegates from all the shortlisted countries will undoubtedly be trying to bump into IOC delegates, accidentally on purpose, in the bars, lobbies and even lifts of Singapore's hotels. But Jowell believes being too pushy could spectacularly backfire.
"Wherever possible I think it is better to have meetings," she says. "What a number of IOC members have said is if, as they put it, the lobbying is too 'in your face', then they just want to lock themselves in their hotel rooms."
Some IOC members say they will run for cover if they spot an approaching lobbyist. "If they want to go the bar and buy themselves a drink and it takes them three hours because of all the city lobbyists they have to negotiate to get there, it doesn't do you any good at all."
A veteran of several election campaigns, Jowell says the quest for votes "is like any election. You have got to give people the chance to welcome you in or slam the door in your face."
With Paris still seen as the front-runner, is London prepared for defeat? "If you are going to go for a prize as great as this, you also have to be prepared that you may be disappointed," she says. The IOC has a history of not picking the front-runner and some think this could work in London's favour. "If Olympic votes are famous for anything they are famous for surprises," Jowell says.
Does this mean London is privately expecting Paris to win? "No I am certainly not acknowledging that at all," she says. "We are going out to Singapore to win. It's as simple as that. If you ask me, 'Do you know we are going to win?', the answer is no."
Jowell does not countenance bidding again if London loses, not least because in future years the derelict East End sites earmarked for the Olympic park will have been built upon: "You would be asking the people of the East End to live with a degree of blight for years if we said we'll keep them until 2016 or 2020."
She says that if a European city wins the games this time it will be the turn of a country in the developing world - South Africa or India perhaps - next time. But regardless of whether London wins, Jowell says there will be a sporting "legacy" from the bid including a velodrome, a hockey centre and an aquatic centre.
"We are determined we are going to win but, if for some reason, we just were pipped at the post by one of the other cities, there would be things that we would want to do," she says. The Government has set up a series of 2012 scholarships for "young people from age 10 upwards who are the very best there are", and more than 100 such young people are already receiving £10,000 a year to encourage them to be "the champions of tomorrow."
But is she disheartened that at Wimbledon, for example, the 18-year-old Andy Murray was the only Briton to make significant progress? Jowell says she wants to see more Andy Murrays, and blames past Governments for failing to nurture the "green shoots" of talent.
"In this country we have for generations squandered the talent of young people with enormous sporting potential because their families can't afford the price of their talent," she says. "You get Andy Murrays by having a big pool of talent to draw from, if you have in place the talent spotting, the coaching and the funding."
The minister has some experience of élite sportsmen herself. Her son, now at university, was discovered as a golf prodigy after being bought some plastic golf clubs when he was four. She says: "The 2012 scholarships were very much inspired by my experience of him. It costs a lot of money to be the parent of a very talented young sportswoman or young sportsmen.
"We were able to send him to an élite academy in Florida that meant that he got the very best chance to succeed. He had friends whose parents were not in a position to do that."
But fostering sport in Britain is not only about nurturing exceptional talent - it is about making sport accessible to fans. Is she concerned that Malcolm Glazer's takeover of Manchester United will lead to a hike in the cost of tickets, pricing fans out of the stands?
"If you have made as much money as Malcolm Glazer has you know a bit about your customers," she says. "Man Utd has an enormous fan base and, frankly, I don't believe that Malcolm Glazer or anyone else would be so foolish as to alienate that fan base, because football clubs exist by virtue of their fans. I do not believe that somebody as astute as Malcolm Glazer is going to put the future of Man Utd in jeopardy."
Pausing, she adds a thinly veiled word of warning to all football moguls: "You lose your fans if they feel they are being ripped off."