Michael Silvey has a full beard, a T-shirt bearing the Welsh dragon and a secret that he is keeping from his wife.

The former train guard from Barry, South Wales, a proud Labour man since he was old enough to vote, may be about to turn Tory.

The prospect provoked a sharp intake of breath. “I’m between the devil and the deep blue sea,” he lamented, raising the issues of immigration, his wife Helen’s recent bout of hospital-acquired MRSA and, above all, the rising cost of living.

Although he will “get his ear bent" by his wife for even suggesting it, Mr Silvey, 64, said that he was tempted to vote for Katherine Kemp, a Conservative candidate for Vale of Glamorgan council, in Thursday’s election.

Four years ago, when Wales last held its all-out council elections, Labour had a terrible night, losing control of the main urban authorities of Cardiff, Swansea and Bridgend.

Despite gains elsewhere that left it with control over eight of the country’s 22 councils, a Liberal Democrat minority administration in Cardiff and Lib Dem-led coalitions in the other two authorities have deprived Labour of power in important places.

It remains by far the biggest single party – independent councillors are the second-largest group after winning 322 seats to Labour’s 478 in 2004 – and Labour optimists argue that some voters will return to the fold, having seen the downsides of change and registered their protest over Iraq.

However, men such as Mr Silvey may in fact be about to make things even worse. “It’s all very well for those people up there claiming their expenses,” he said, as he complained about the problems of coping with rising prices on his incapacity benefit and his wife’s pension. “The price of things is going up all the time. It’s difficult to pay for petrol.”

He dislikes Gordon Brown – “I don’t want to swear but he’s done some silly things” – and said, in an echo of the 10p tax debate, that Labour had neglected those who should be the party’s core base.

The defection of Mr Silvey may prove crucial. The Conservatives need to overturn a majority of only 38 votes to take a seat from Labour in his Dyfan ward, and only four new seats to take overall control of Vale of Glamorgan council from the current Labour-Plaid Cymru coalition.

If the Conservatives succeed there, and hold control in Monmouthshire, the number of Welsh councils coloured blue on the political map will rise to the grand total of two.

Wales has never been particularly fertile ground for the Conservatives. Any gains in places such as Cardiff and Newport may say as much about Labour’s problems as about the Welsh taking the Tories to their hearts.

Cardiff could prove to be a microcosm of Labour fortunes across Wales if, as some are predicting, the party is squeezed from all sides. The Liberal Democrats and the Conservatives are hoping to pick up seats, while Plaid Cymru could also hit Labour.However the Welsh nationalists’ Assembly coalition with Labour might tarnish them with unpopularity by association in a scenario that could play out across the country.

Away from the urban sprawl, Labour faces another once unthinkable prospect – that of losing control of Blaenau Gwent to the combined forces of People’s Voice, the local party that holds the Westminster and Assembly seats, and independents.

However, it is in Newport where the greatest symbolic blow could be dealt. After the losses of 2004, the city is the last of the big urban Welsh councils to remain in Labour hands.

“It is the last bastion, the last socialist city in Wales,” said Matthew Evans, the gleeful Newport Conservative group leader, “and we are going to breach it.”

Nobody expects the Conservatives or Liberal Democrats to take overall control of a council where they currently have 12 and 6 seats respectively compared with Labour’s 30.

The Liberal Democrats came close to taking Newport East in last year’s Welsh Assembly elections, however, and the Conservatives are confident that the opposition parties are capable of depriving Labour of a majority.

Bob Bright, Labour’s council leader in Newport, did his best to sound hopeful when asked if he will keep his job: “I’m going to be ebullient, I’m going to say yes.”

But his words also revealed a frustration that the Government’s national predicament, and in particular the economy, might undo the good regeneration work that he says Labour is doing locally: “Newport is the best piece of electioneering we have but it’s very difficult to get that message across,” he said, expressing fears that Labour supporters might not turn out because they assume the party is secure. “That is not the case this time.”

The battleground

— All 1,262 seats across the 22 Welsh local authorities are being contested, although the death of a candidate in Newport means that one three-seat ward will not be contested until a June by-election

— Labour has overall control of eight councils. There is no overall control in nine councils, Plaid Cymru and the Conservatives hold one each and three are run by independents

— Labour is fielding 877 candidates, compared with 519 for Plaid Cymru, 514 Conservatives, 437 Liberal Democrats, 718 independents and almost 200 candidates from smaller parties

— After the 2004 elections Labour had 478 councillors, independents had 322, Plaid Cymru 174, Liberal Democrats 146, Conservatives 107 and assorted others 35

— In last year’s Welsh Assembly elections Labour lost four seats while Plaid Cymru gained three, leaving them with 26 and 15 seats respectively. The two parties formed a ruling coalition. The Conservatives have 12 seats, the Liberal Democrats six and there is one independent

The targets

Labour Fighting a predominantly defensive campaign with a lot of seats at stake. It would take a good night for the party to retake Bridgend and/or Swansea, which were both lost in 2004

Plaid Cymru Lost two of its three overall majorities last time, in Caerphilly and Rhondda Cynon Taff, where it suffered big losses. Will want to make decent gains in the former as well as in Ceredigion, where it is now the largest party, and Carmarthenshire

Liberal Democrats Had big wins in 2004, for example becoming the largest party in Cardiff. A better than expected evening could allow them to gain overall control in the Welsh capital.

Conservatives Hope to take control in Vale of Glamorgan and to pick up seats in Cardiff and Newport. Currently the fifth party of local government in Wales

Other People’s Voice, fighting its first council elections, says it is going for the “grand slam” by taking Blaenau Gwent from Labour after winning the Westminster and Assembly seats. It may need a coalition with independents

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