Britain's smaller parties will today be hoping that voters look beyond the 'big three' and consider the other options on the ballot paper.

European elections and devolution in Scotland, Wales and London has, with varying forms of proportional representation, given smaller parties the experience of elected representation.

Now many of them are aiming to make the transition to Westminster, but with the first-past-the-post system still in place they will all struggle to make gains.

Greens

With record numbers of councillors, two MEPs, seven members of the Scottish parliament and two London assembly members, the Greens are hoping they can finally add an MP to their list.

Their best chance is in Brighton Pavilion where councillor Keith Taylor has been running a high profile campaign.

Not surprisingly, the Greens have centred their appeal to the electorate on environmental concerns, with tackling climate change their number one priority.

They also advocate renationalising the railways and scrapping the private finance initiative, tuition fees and top-up fees.

Greens are also targeting the decision to invade Iraq, hoping that they will pick up protest votes from disaffected Labour supporters.

Even if they do not make the breakthrough they want this time, the Greens will be hoping to gain enough support to influence the major parties and show growing public support for policies that would promote sustainable development.

UKIP

In last June's European parliamentary elections, the UK Independence Party shocked the political establishment by taking 10 seats.

Much of their success was due to their recruitment of former chat show host Robert Kilroy-Silk who gained them acres of publicity.

However, the party's hopes of replicating their success in the Westminster election evaporated when Kilroy left to form his own party after being denied the leadership.

But the party which wants Britain to pull out of the EU and promises to "take a firm line on immigration" still has an influence on UK politics.

The threat of UKIP, which pushed the Tories into fourth in the Hartlepool by-election, may have contributed to the Conservatives taking such a tough line on immigration and other "dog whistle" issues.

Europe, however, has not featured very highly on the election agenda this time. And with little media coverage, UKIP may see support slip today.

Veritas

Kilroy-Silk's political ambitions were not dulled by his experience with UKIP, and the MEP soon set up his own anti-European party - Veritas.

The former Labour MP believes people are "tired of the lies, the deceit, the evasions and the spin of the old parties in Westminster," and wants his party to make a difference.

Kilroy was joined by UKIP's two London assembly members who were similarly annoyed with their former party's lack of "drive and organisation".

Despite lacking funds, Kilroy hopes his promises to pull out of the EU and reject multiculturalism will appeal enough to send him back to Westminster.

Respect

George Galloway is another ex-Labour MP hoping to shake up the political establishment.

Expelled from his former party for comments during the Iraq war, Galloway is hoping to win Bethnal Green and Bow for his Respect coalition, defeating Labour's Oona King.

The anti-war party is hoping to attract the votes of Muslims and others angry at the war in Iraq.

And its left-wing agenda may also appeal to traditional socialists disillusioned with New Labour's move to the centre of the political spectrum.

Scottish Socialist Party

With six members of the Edinburgh parliament, the Scottish Socialist Party is now hoping to win its first seats in Westminster.

The anti-capitalist party is aiming "to build a socialist Scotland that will stand up to global capitalism and spearhead the fight for a socialist Europe and ultimately a socialist world".

Like Respect south of the border, the pro-independence SSP will be hoping to capitalise on anti-war feeling among anger among left-wingers.