Amid noisy children, he shares his thoughts on the last stretch of the long march with Stephen Castle
A Police guard stands outside the Islington home of Tony Blair, but behind the front door it does not look like the base of a prime minister in waiting. A football clutters the hallway. In the living room, Mr Blair is disturbed at frequent intervals by youngsters. The phone rings and suddenly Cherie's voice, rather than Tony's, fills the room. Only after a plea to quieten down can we get back to the business in hand, the countdown to a victory Mr Blair now seems to expect.

Last week he raised eyebrows by saying, on an afternoon walkabout, that the sun was out and the Tories would be too in a couple of weeks. He denies that was a victory claim, but none the less thinks the mood changed last week. Although Europe has dominated the headlines (with Mr Blair playing his own more sceptical part in them), it is not the internal Tory difficulties that excite him. The Labour leader thinks his party is making a breakthrough despite, and not because of, Westminster campaigning.

Broadcasters, now devoting hours to the election, get little thanks. Much of the output, he argues, demonstrates "a conspiracy against understanding". The Labour leader, like much of the population, is tempted to switch off: "I can barely bear to watch it myself, so heaven knows what most people out there are making of it."

The blame for this is placed on the Conservatives. Mr Blair argues: "My view now is that they, quite deliberately, chose to have a long campaign and try to bore people, grind them down so that everyone concluded there's no real difference ... they're all the same these politicians ... can't stand it any more ... let's stick with what we've got - it was a typical low-grade strategy."

Labour's progress has been made on the ground, on regional bulletins and on items further down the news schedules, talking about bread-and- butter issues with a little more passion, Mr Blair thinks. There has been "a significant change", with Labour having "loosened up a bit in our campaigning". That is code for the shift of gear after the previous week's troubles over privatisation and the economy. In the strategists' jargon, Labour has moved from trying to reassure the electorate about tax and the economy - press conferences centred around the "Iron Chancellor" etc - to persuading it that Labour would make a difference. That style of campaigning suits Mr Blair. "The campaign is beginning to come alive. There is a strong perception that we are talking about clear, gut issues that should determine the election, and I think the Tories have made a terrible mistake in engaging in a purely negative campaign."

He is angry at the "left" argument that because he does not want to raise tax, his party could make no real difference. "What we have been offering in terms of change this week is a decent society, social cohesion, extending educational opportunity, a fair deal for pensioners. There is a good centre- left agenda. We can make things different. We are going to make a difference. The values are different, the priorities are different."

Mr Blair is sitting upright in a chair in the room once described as so formal it could be a hotel room. In fact it has a lived-in feel, and Mr Blair, in casual blue cotton shirt, looks like a man about to relax with his family. Naturally, he could be merely acting out the role of a relaxed politician, to counter Tory claims that he is a man "cracking under the strain". If so, it is effective. The Labour leader appears to be in weekend-ish mood, less than two weeks before he can expect to move a few miles down the road to Downing Street. He seems less anxious about it than the average family would about an ordinary house move.

In personal terms, Mr Blair has had to take the brunt of much of the Tories' latest attack, being depicted last week in newspaper adverts sitting on the knee of Chancellor Kohl. It did, not, he says, make him angry although it was "the act of a desperate party".

"The Tories," he says, pulling few punches, "are a degenerate party". Mr Major is "always fighting for a job, never fighting for a vision".

Conservative tactics over Europe have been to make a virtue of necessity. Last week began with ministers defying the party's line on the single currency, and escaping without the sack. Mr Major went on the attack, appealing for unity, then arguing that sending Mr Blair to the negotiating table would be like sending a fly to a spiders' convention.

But Labour has moved in a sceptic direction, too. Last Monday Mr Blair said that like Mr Major, he would be willing to be isolated in Europe in the national interest. On Thursday, asked about the single European currency, Mr Blair hardened the position, which had been to identify the barriers to European Monetary Union (EMU) as economic, rather than constitutional. Now he argues that he sees no "insuperable" constitutional barrier.

"People are concerned about the direction of Europe. They are worried about it, they think that Britain is not being treated fairly," he says. The answer, he thinks, is to rebuild a relationship with Europe in which Britain can exercise proper leadership.

"You must," he says, "always be prepared to be isolated if it is in the national interest to be so. What the Conservatives have done is to take a sentence, wrench it out of context and suggest that what I meant was that I would never have Britain in a minority of one in any set of circumstances. That would plainly be fatuous. Of course if it were in the country's interest to be isolated, then you're isolated."

He goes on to outline the circumstances that could lead to that self- imposed isolation. "It is important that we recognise that the people of Europe want co-operation between independent nation states; they don't want a federal Europe. It is important that we allow Europe to grow and change from the bottom up, not the top down." Almost as an afterthought he adds, "But it is important that we are part of Europe and we are engaged in Europe."

On the single currency, the balance of the language has changed too. EMU has, Mr Blair says, "constitutional implications and political implications, of course it does. You are yielding up control over part of your economic policy so of course it's got political and constitutional implications. The question therefore is, do you rule it out because you say it is an insuperable constitutional barrier. Certain people would rule it out - that's not my view."

But nor does he appear to rule it in. "You are yielding up the ability to get the exchange rate flexibility, which is one way of dealing with changing economic circumstances; there isn't the same labour mobility that there is in other single currency areas, and there is no appetite for large physical transfers from the centre to mop up economic problems that occur as a result of economies moving out of step with one another. But we will be affected by a single currency whether we're in or out of it; it is important that Britain both retains influence over the process and the option to go in if it wishes."

There is no question of giving up revenue-raising to Brussels: "I don't agree with giving up taxation powers."

That does not sound like a man preparing to take Britain into EMU in the next parliament, but Mr Blair says the options are open.

As he gets up to rejoin the family, Mr Blair rejects any notion of a grand first 100 days in office. Such things have a habit of fizzling out.

The broader message is that Labour now offers change without risk, attainable objectives with minimal danger. The recipe is bringing power closer by the day.