Mr David, the Euro MP for South Wales Central, would win Tony Blair's backing to become First Secretary in the Cardiff assembly if Mr Michael, the Secretary of State for Wales, was not elected to it.
Until now, it had been assumed that, if Mr Michael failed to win a seat, there would be a battle between Rhodri Morgan, the maverick MP for Cardiff West, and Ron Davies, who resigned as Welsh secretary last October after his "moment of madness" on Clapham Common in south London.
Senior Labour figures insisted yesterday that they remained confident Mr Michael would win his battle to be elected in the Mid and West Wales region in tomorrow's election under the "top up" system of proportional representation (PR).
But the same sources told The Independent that, under a contingency plan, the leadership would back Mr David if Mr Michael was defeated. The final decision would be left to the party members who won seats in the assembly and the Blairite-dominated executive committee of the Welsh Labour Party.
Mr David, a former leader of the British Labour Euro MPs in Strasbourg, is seen as a "safe pair of hands" by Mr Blair, even though he was judged to lack the charisma to lead the party's campaign when Mr Davies resigned from the Cabinet.
Defeat for Mr Michael would be a huge embarrassment for Labour, plunging it into its third leadership election in Wales in nine months. Mr Davies saw off Mr Morgan, who then narrowly lost to Mr Michael after Mr Davies resigned. However, Mr Michael's prospects were given a boost last night when the last all-Wales poll before tomorrow's election suggested that he would land a seat under PR.
The NOP survey for HTV predicted that Labour will win an overall majority of eight seats in the new assembly. It gave Labour 47 per cent of the vote, suggesting that it would gain 34 of the 60 seats. Plaid Cymru gained 26 per cent of the vote, giving it 13 seats. The 14 per cent Tory share of the vote would be a considerable reduction on its 1997 general election performance in Wales and would yield seven seats, while the Liberal Democrats (10 per cent) would win six. At the general election, Labour won 54.7 per cent of the vote while Plaid Cymru got just 9.9 per cent.
Voters rated Dafydd Wigley, leader of Plaid Cymru, as the best man for the job of First Secretary. Mr Wigley received 42 per cent of votes, compared with 39 per cent for Mr Michael. Rod Richards, the Welsh Tory leader, got 13 per cent and Mike German of the Liberal Democrats 6 per cent.
Gordon Brown, the Chancellor, rallied to Mr Michael's cause yesterday when he spearheaded a drive to boost Labour's vote by campaigning in Wales. "There is no person better suited to bring together business, government and the voluntary sector in Wales," he said of Mr Michael.
Both the Chancellor and Mr Michael concentrated their fire on Plaid Cymru. Mr Brown warned that the nationalists would create "constitutional chaos", which would drive away businesses and jobs.
At a press conference in London today, Mr Blair will make a last-minute plea for people to vote in tomorrow's elections to local authorities, the Welsh Assembly and the Scottish Parliament. Labour officials are worried that there will be a low turnout in the council elections because people are broadly content with the Government.
Mr Blair also sought to combat voter apathy in a party election broadcast last night. Urging people not to put the Government's achievements at risk, he said: "We need local and national government working together. The Conservatives are a mess. We can offer the leadership this country needs."Reuse content