France's sixth biggest city* goes to the polls (*that's London, by the way)

The English capital has more Gallic residents than Calais and Lille combined. And next month expats in the stronghold of South Kensington will have a big say in who is returned as the first French overseas MP

Across the UK, a general election campaign is beginning to gather pace. It may have gone unnoticed but, be assured, canvassing is in full swing; supporters are going door-to-door and the candidates are engaging in political tête-à-têtes at the hustings.

The second homes, though, are not in the Home Counties, they are in Paris; the Conservative and Labour parties will not win a single seat between them and, instead of eggs, the candidates could find themselves dodging oeufs. France is going to the polls next month and they are electing the first ever "MP for South Kensington".

Eleven new overseas constituencies have been created for the coming parliamentary elections, which will take place over two rounds on June 10 and 17, allowing French expatriates to return an MP to the Assemblée Nationale for the first time. Ten nations, including the UK, are grouped into the "northern Europe" constituency. Figures show that between 300,000 and 400,000 French people live in London alone prompting some to call it France's sixth biggest city.

And, at more than 120,000, the Gallic community in Britain registered to vote is more than five times larger than those in the other nine countries which make up the constituency. A large proportion of their number live near to the French language school, French consulate and French cultural institute in west London's French stronghold of South Kensington.

The candidates, however, face a major obstacle to getting the vote out. There are plenty of French people to canvass. But, in a constituency which is more than 1.5 million square miles in size, they are struggling to find them. "I feel like I am a backpacker, with my leaflets in one hand and my passport in the other. I feel like a pioneer," said Axelle Lemaire, the candidate put forward by new President François Hollande's left-wing Parti Socialiste. She added: "We have done some door-to-door canvassing, we have knocked on around 1,500 doors; that itself is a huge amount of work. Finding the original addresses, looking them up on a map, getting there: in two hours, you can see five to ten people on a good day."

Her main rival, the candidate standing for the centre-right Union pour un Mouvement Populaire, Emmanuelle Savarit, agreed. At a meeting with supporters held last week – perhaps predictably – in a small restaurant opposite the French Cultural Institute, she implored them to each canvass 10 people, and have them tell 10 people in a bid to get the word out.

And the candidates have 10 days until the polls open. "We are looking for people to do door-to-door work. If you have a network of friends, then please use it. I meet people who wanted Sarkozy elected but who just didn't go and vote. I meet people who said they were really opposed to Hollande but they were on holiday when the polling booths were open. It's terrible," said Ms Savarit.

And then there are the everyday problems Anglo-French life poses. At one hustings meeting last week, one candidate Olivier de Chazeaux, was forced to send his deputy to speak after he was stuck on a Eurostar train.

Whichever of the 20 candidates wins the seat, they will be expected to be involved in French national politics as well as to represent their constituents' more specific needs. For many expats, those will include help with paperwork and ensuring experience and qualifications gained abroad are properly recognised on their return to France. For others, staving off the new President's mooted tax increases and the removal of benefits for expats will lead the debate.

"A lot of MPs don't know what it is like to live abroad, it is important because our voices sound very different. In London, economically, we have different views to back home. We are more on the front line. François Hollande is proposing a tax of 75 per cent and is mentioning that he might or might not tax us, now we'll have someone to represent us," said Jean-Philippe Germain, a 29-year-old Savarit supporter from Grenoble who lived in Paris before moving to London five years ago to work for an investment bank

But Ms Lemaire said she is determined to take some of the lessons she has learned in Britain back home. "When I look at the Leveson Inquiry, I feel the British Parliamentary inquiry system seems more powerful than in France. There is more accountability and transparency, it is a political and cultural difference, so that is something I think could change," she said.

Despite a campaign spending cap of around £55,000, the candidates intend to travel as much as possible, although most of the campaigning is done by email. Nevertheless, given the high proportion of the expatriate community which lives in two main mini-diasporas in London, the capital is the most likely to see campaign posters and French candidates beating the leather.

Guillaume Féry, 41, who works for energy firm EDF and has lived in London with his family for two years, warned that the candidates also faced election overload and voter apathy. "It is difficult because it is so soon after the Presidential elections and people do not know the candidates," he said.

"It is a good idea but I am not sure how realistic the plan is. Only a third of French people in the UK actually voted in the presidential election, so are they really that interested?"

French connection the numbers

300,000 Lower estimate of the number of French people living in London.

347,000 The number of French people living in Nice, France's fifth largest city.

20 The number of candidates vying for one seat in the North Europe consitutency, which spans 10 countries.