Paddy Ashdown says that the Liberal Democrats are on course to pull off a surprise victory in the Conservative-held seat of Maidstone and The Weald.

The former party leader was in the town to lend his weight to the campaign, which he said could be one of the surprise results on May 7.

He joined activists and candidate Jasper Gerard to urge them to redouble their efforts in the final weeks of the campaign.

He said the contest reminded him of how he had made an historic parliamentary breakthrough when he won the seat of Yeovil in 1983 against expectations and after decades in which it had been held by the Conservatives.

“It took me eight years to win Yeovil but it had been Tory since 1910. They didn’t count their vote, they weighed it and people said it would be impossible to win. It is not impossible here. “

“This seat, like many others, will be decided by plus or minus a thousand or so votes. There is everything to play for.”

Mr Ashdown’s visit followed one by party leader Nick Clegg earlier this week and underlines the increasing optimism within the party that it could spring a surprise.

He said that the Lib Dems were not doing as badly as national polls suggested.

“The national polls are not a reflection of where the Liberal Democrats are in individual seats. I know how close we are to winning here. I have seen the polls, we are not there yet but we are within a whisker.”

He took a sideswipe at Conservative candidate Helen Grant, saying that “Maidstone could do better with Jasper Gerard.”

Earlier, he had rallied party supporters gathered in Cornwallis Park to give him a reason to shout “yeah!” on election night by returning a Liberal Democrat MP in the county for the first time.

The Conservatives hold the seat with a majority of just under 6,000.