Minority parties - From fringe to centre-stage

While teams of strategists for the three main political parties have been scratching their heads and poring over electoral maps to decide how best to maximise their return of parliamentary seats, the three smaller parties have a much more straightforward task in deciding where to deploy their limited resources.

The Green Party, the UK Independence Party (Ukip) and the British National Party (BNP) each has one obvious constituency in which to focus their efforts as they attempt to secure a seat in the Commons for the first time.

It is no surprise that the Green Party, after decades of playing the role of plucky outsiders, believes the 2010 election offers its best-ever chance of doing so. Climate change has rocketed up the agenda, while the professionalism of the party's backroom operation has improved markedly in recent years. As a result, its support has tripled over the last decade as it has targeted its efforts at the most winnable seats.

It is a strategy that will be repeated at national level. Insiders believe they are "within striking distance" in Lewisham Deptford and Norwich South. But in reality, their efforts are focused on helping their leader, Caroline Lucas, secure victory in Brighton Pavilion. It is in this middle-class, progressive constituency, currently held by Labour, that the party has based its target constituencies team, run by Ms Lucas's campaign manager, Paul Steedman.

Good will seems to be with them, with party officials believing they have more volunteers out canvassing than either the Tories or Labour. The party has suffered from tactical voting in the past, with the electorate regarding Green votes as wasted, but this time it hopes it will be seen as the best chance of preventing a Tory win in Brighton. Labour's task of holding on to the seat will be made even tougher as the long-term incumbent, David Lepper, will not be standing for re-election.

The difficulty, as ever for the party so associated with a single issue, will be deciding how far to push its other policies. Striking the right balance is the task of Tracy Dighton-Brown, the party's external communications co-ordinator. She thinks the Greens should start pushing their broader agenda where they have already performed well in local and European elections. When she arrived in the post in September 2008, she conducted a review of all communications sent out by Green councillors, as well as running focus groups to determine which policies were playing well with potential voters who had previously backed Labour or the Liberal Democrats.

The conclusion was that the party should push its ideas on job creation and its vision of developing a green economy, a positive message that steers away from the doom-laden prophesies about the dangers of climate change. Pledges on the NHS and a costed promise to raise the state pension to £175 a week will also be used to broaden the party's appeal to those pondering whether to back the Greens for the first time.

For Ukip, the best chance of a Westminster breakthrough will come in the true blue seat of Buckingham, where the party's former leader, Nigel Farage, hopes to oust the Commons Speaker, John Bercow. Precedent dictates that the main parties do not run against the Speaker, but the constituency offers Mr Farage a unique chance of success.

On the face of it, victory for Mr Farage seems improbable. At the last election, when the seat was contested by the other parties, Mr Bercow's majority was a colossal 18,000 votes over Labour; Ukip limped home with just over 1,400 votes. But Mr Bercow's position on the far-left outposts of the Conservative Party has led Ukip's leadership to believe that he is vulnerable to an attack from a candidate who espouses the traditional messages of the Tories.

National strategy is overseen by the party's new leader, Lord Pearson, and the campaign director, James Pryor, who formerly advised Margaret Thatcher and John Major. No doubt it is Mr Pryor's involvement that has led Ukip to focus on Tory heartland issues such as grammar schools and clamping down on crime, as well as on its popular anti-EU message. However, the profile that Mr Farage has built for himself, through the odd outburst in Brussels and his aggressive performances on Question Time, means that he is largely left to run his own show in his quest to win the Buckingham seat. The party reckons it is his strong performance at hustings that will win him crucial Tory votes, so the strategy is simple – long days on the campaign trail.

Recent successes have buoyed party officials. They believe Ukip's strong performance in the Norwich North by-election last year went largely unreported. All the attention was on how the Greens would perform, but it was Ukip that made the biggest leap, with a swing in their favour of nine per cent. The party secured more than 4,000 votes – only 800 behind the Liberal Democrats, and enough for them to beat the Greens to fourth place. Resources have already been found to fight a high-profile campaign in Buckingham, with Stuart Wheeler, the spread-betting millionaire who has previously donated to the Tories, handing around £100,000 to Mr Farage's campaign.

Its performance in the election will depend on how well it can present a united front to voters. The party has already shown it can damage itself with internal wrangling. Even when Mr Farage was pushing the party's popularity to new highs, people within the party were plotting to bring him down as leader. The in-fighting has continued. Nikki Sinclaire, who had been one of 13 Ukip MEPs, was thrown out of the party earlier this month after she refused to sit with her party colleagues. She had been protesting at the party's decision to join the Europe of Freedom and Democracy (EFD) grouping, which she said contained some politicians harbouring "extreme views".

Finally, what are the prospects for the BNP? Securing two seats in the European parliament last summer has helped the party enjoy unprecedented levels of media exposure. It will use that notoriety to launch an assault to win the east London seat of Barking for its leader and chief strategist, Nick Griffin. The constituency delivered the party its best-ever general election result in 2005, when it received a 16.9 per cent share of the vote. It also has nine councillors in the area.

During the campaign, Mr Griffin will be given a chance to capitalise further from heightened media coverage. Along with Caroline Lucas and Nigel Farage, he will be able to respond to the main party leaders' television debates on news bulletins after the main event.

In an attempt to professionalise the party, Mr Griffin is also taking measures to improve its handling of the media. Enquiries had previously been handled by the deputy chairman, Simon Darby. But supporters have been asked to donate towards the costs of a new communications department designed to fight back "against media smears". Its website has already been vastly improved by the party's online manager, Simon Bennett. As well as its vehemently anti-immigration message, it will again attempt to capture the "anti-politics" vote at the next election. Incumbent MPs will be attacked for their involvement in the expenses scandal.