Trainspotting star Robert Carlyle has emerged as the favourite to take over from David Tennant as the new Doctor Who.

While Jason Statham, Alan Davies and the Cold Feet star James Nesbitt have also been tipped to step into the Time Lord's shoes, Carlyle is the new frontrunner, according to bookmakers.

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New Who? Robert Carlyle (left) is tipped to replace David Tennant as the 11th Time Lord

There is wide speculation Tennant will step down before the start of the BBC's fifth series in 2010 - but he has refused to confirm the rumours.

However, viewers who watched him recovering from a Dalek attack over the weekend saw him begin what appeared to be his cyclical regeneration process.

The final of the fourth series is set to air this Saturday, with the plot line remaining a closely guarded secret.

A spokeswoman for the series said: 'There's a limited amount of information on the website about the final episode, but it's fair to say we want to keep it quiet. In fact, we want to keep it as secret as possible.

Battle: Dr Who's old enemy, the Daleks

'We put a block on sending out preview tapes so no-one could find out how it ended. We even chopped off the last few minutes of the tapes for the 12th episode so there would be no clues.'

Bookmaker William Hill is offering odds of 2-1 for Carlyle, with a spokesperson adding: 'We get lots of calls from Dr Who enthusiasts who want to put bets on the next Time Lord.

'Robert Carlyle is currently the favourite but it changes all the time.'

For his part, Carlyle hasn't ruled out playing the 11th Doctor, saying:  'Would I do it? Possibly.'

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Under attack: The penultimate episode, called The Stolen Earth, was watched by 7.4 million people on Saturday