As polling day nears, the election campaign in Wales, in part mirroring the national situation, has become an exercise in psychology.

The latest polls indicate that Labour remains dominant in Wales but, as ever, a number of factors at work in local constituencies could yet take the shine off a victory or offer a veneer of respectability on the night.

On Sunday, Plaid's candidate in Rhondda, Leanne Wood, claimed her party was "running neck and neck" with Labour in the constituency and said the result was too close to call.

On Monday, Labour claimed it was level pegging in the Ynys Mon constituency, which the nationalists won in 1997 and where the party's president, Ieuan Wyn Jones is stepping down from Westminster to concentrate on his work in Cardiff.

As both parties seek to persuade voters that a vote for them would not be wasted and remains as important as ever, a complicated game of double-bluff is being played out with no one being entirely sure of outcomes that are unpredictable in a number of constituencies.

The first post-Welsh Assembly general election campaign in Wales has seen a number of new developments.

Three of the four main parties have offered the electorate varying degrees of constitutional change, but this time with Labour offering the more conservative set of proposals.

And both Labour and the Liberal Democrats have had to work out how to fit their partnership in the National Assembly into the elections.

For the Lib Dems that has meant hailing their achievements of being in government at all and pushing Labour in Wales to be slightly more radical than Labour in Westminster - within the limited scope the Welsh Assembly has for doing things differently.

Labour, it seems, have found it easier to ignore the Liberal Democrats and instead have concentrated on warning of the dangers of a nationalist vote letting in the Tories, and the dangers of letting in the Tories.

As Welsh Secretary Paul Murphy described it: "William Hague has two hopes in this election. The first is that the Tories will win seats and votes. The second is that the Welsh Nationalist Party will win seats and votes. For the nationalists are William Hague's little helpers."

In more knock-about campaigning at Plaid's expense, and sensibly avoiding Welsh stereotyping, Labour also unveiled its "whingeometer" in the final days of campaigning, with which the party measured the "whinge factor" in the nationalists' campaign. On Tuesday morning Labour was giving Plaid a whinge-rating of 84 per cent "after another 12 hours of Nationalist carping".

Plaid Cymru has been placing its emphasis on the twin pillars of more powers for the Welsh assembly and incresed spending. It wants to match the powers of the Scottish parliament - although party president Ieuan Wyn Jones did face a tricky moment during a BBC interview when he admitted that the manifesto's stated aim of tax-raising powers was a mistake as the aim was to match Scotland's tax-varying powers. Plaid also makes the case for increased spending on public services.

In opposition in the Welsh assembly, following its surprise victories in the 1999 assembly elections that denied Labour its expected majority, Plaid has sought to present itself as the only voice standing up for Wales.

With an avowedly socialist manifesto, the party will be hoping to retain some of the votes it gained in 1999.

Though with Rhodri Morgan now leading Labour - rather than Alun Michael and the widespread, if unfair, feeling that he was "London's representative in Wales" - and the absence of any suggestion that this election is solely about Wales, the nationalists have been keen since the beginning of the campaign to emphasise that their result this time should be compared with 1997 rather than 1999.

In those terms, Plaid is likely to see an improvement on its 1997 share of the vote, from 10 per cent last time to around 15 per cent this time, according to the latest polls, but this may not be enough to win the party any more seats.

However, Ieuan Wyn Jones said his party is on course to secure its best ever general election result. Plaid was "confident but not complacent" that it would return to Westminster with more MPs and a much higher share of the vote than in 1997.

Opinion polls also make the Welsh Conservatives the second most popular party in Wales, on around an 18 per cent share of support. Despite this, the party faces an uphill climb to win back the seats it lost in 1997 when it was wiped out in Wales.

One of the Conservative's key targets is Clwyd West, where the 1999 assembly elections saw just 938 votes separating Labour in first from Plaid Cymru in third. With Labour's Gareth Thomas battling to defend a majority of 1848, the seat is vulnerable to a swing of just 2.3 per cent.

While Plaid was further back in 1997, the willingness of voters to switch to the party from Labour could enable the Tories to snatch the seat back from Labour, if their own vote holds up.

As the campaign draws to a close, all parties will be awaiting the verdict of the Welsh people - this time perhaps a little more keenly than usual.