Mr Ashdown has admitted in a 'private and confidential' letter to activists that a strong Labour campaign could stop his party from securing the seat and has exhorted activists to travel to the Hampshire constituency to sustain the Liberal Democrats' momentum.
Mr Ashdown insists that, 'of course, nobody takes Labour's chances of winning seriously', but in deference to the stated aim of the Labour Party to win the by-election, he adds: 'A strong Labour campaign could stop the Liberal Democrats winning. The Conservatives are talking up Labour's chances in the hope of splitting the vote against them.'
Mr Ashdown's letter, leaked to Labour, warns: 'I have to tell you that I am absolutely convinced that this by-election will not be a 'push- over' for us.'
The letter underlines that Labour's campaign to go all-out to win the seat is causing dissension in the opposition ranks.
A senior Liberal Democrat official said last night that Mr Ashdown's letter had been to 2,500 people in the party and added that it was 'intriguing' that Labour were publicising it. It underlined that 'Labour could stop the Liberal Democrats beating the Tories and teaching them a lesson' but also that it could not win the seat.