Blair tops leadership polls: Cook will stand as left's challenger to Labour 'modernisers' - Beckett urges unity in run-up to Euro elections

OPINION polls published today make Tony Blair the clear front-runner to succeed John Smith as the contest threatens to become a classic left-right Labour Party battle.

Robin Cook, the shadow trade and industry secretary, emerged yesterday as a likely challenger for the leadership, increasing the prospect of an ideological battle between the party's traditionalists and modernisers.

Mr Cook is seriously considering standing for the job left vacant by Mr Smith's death last week, his allies said. No final decision will be made before Mr Smith's funeral on Friday.

However polls by ICM in today's Sunday Express, by Gallup in the Sunday Telegraph and a Mori telephone poll in the Sunday Times all make Mr Blair, the shadow home secretary, the public's favourite to lead Labour.

He has a lead of between 11 and 15 percentage points over his closest rivals, John Prescott and Gordon Brown. Mr Blair's lead is smaller among Labour voters but remains substantial. Mr Cook is bottom in every poll - none gives him more than seven per cent. They were carried out after Mr Smith's death.

Mr Cook's probable candidature ensures at least one candidate from the party's left when the election takes place, almost certainly in July. John Prescott, the shadow employment secretary, could be another: his allies argued yesterday that Mr Cook's early apparent entry to the race could rebound on him. They can also point to today's opinion polls, which show that Mr Prescott is far more popular than Mr Cook both among the public and among committed Labour voters. He is running second to Mr Blair both among the public and among Labour voters.

However, Mr Blair and Mr Brown, the leading contenders from the right, are looking increasingly reluctant to stand against each other. Mr Blair's firm lead in today's polls could create pressure on Mr Brown to stand down. But the shadow chancellor's supporters insist that he cannot be counted out.

The odds on a Blair win increased last night when Labour's arch 'fixer', Peter Mandelson, MP for Hartlepool, and a close friend of Mr Brown virtually spelled out the terms of a Blair-Brown pact. 'Who would fully maximise support for the party in the country?' he asked on Channel 4's A Week in Politics.

Before putting themselves forward, contenders had to consider 'who will play best at the box office, not simply appeal to the traditional supporters and customers of the Labour Party.'

Some modernisers warn that traditionalist Labour members and trade unionists abhor the media 'froth' in favour of Mr Blair. Under the 'one member, one vote' system pushed through by Mr Smith last year, constituency Labour parties and trade unionists together make up two thirds of the electoral college. Supporters of Mr Brown argue that their man might have stronger backing among the mass membership.

The first signs of a potentially divisive battle began to emerge yesterday as the acting leader, Margaret Beckett, tried to damp down electioneering. She appealed to the potential candidates not to speculate about the succession until after the European Parliament elections on 9 June. Labour sources said: 'They have all agreed that this must be the case.' But the self-denying ordinance - already under strain - is likely to break down after Mr Smith's funeral in Edinburgh on Friday.

Mr Brown and Mr Blair have met since Mr Smith's death but are unlikely to reach any agreement or pact until next week.

Supporters of both men believe it is vital to present one strong, modernising candidate who offers greater clarity, more radicalism and more specific policies than Mr Smith did, while building on his ability to include all shades of opinion.

Mr Prescott's allies believe that the deputy leadership, now occupied by Mrs Beckett, could be contested at the same time as the leadership. Mrs Beckett would, in any case, be open to a later challenge. However, the trade unions, who finance most of the estimated pounds 1.5m cost of the election, are unlikely to want two separate contests, Mr Prescott's allies said.

That could revive talk of a Blair/Prescott dream ticket, earlier dismissed when it became clear that a July contest was the widespread wish of the party. Some senior Labour figures argue that Mrs Beckett could secure her position as deputy leader if she decided not to stand for the leadership.

Labour after Smith, pages 17-19; leading article, page 20; the last dinner, Business