The number of Liberal Democrat party members has almost halved in the last five years, an analysis has suggested.

The figure has plunged from just under 118,000 in 2020, when Sir Ed Davey became leader, to 60,000.

That is despite the Lib Dems having their most successful general election ever last year in terms of seats won.

A party spokesman told the BBC, who did the analysis, that “in actual elections, more and more people are backing the Liberal Democrats”.

Professor Tim Bale, who leads a party membership project, said the drop in membership was surprising given the Lib Dems’ electoral success, which would suggest “a party on the up, in which case you might get more ambitious people wanting to join it”.

But he added: “There’s an extent to which surges into parties are prompted by public profile… and they don’t seem to have much chance of getting into government at the moment.”

The Liberal Democrats saw a significant boost in membership in the run-up to Brexit in 2020, when the party was campaigning for a second referendum.

The drop in paid-up members since then has been masked by the inclusion of “registered supporters” in figures published in the party’s annual accounts each year since 2017.

Registered supporters sign up for free to get access to briefings and events but they cannot decide policy or vote in leadership elections.

The party clearly states the figure published in the annual accounts relates to both member and supporters but it does not provide a breakdown, the BBC said.

But figures suggested a greater proportion of Lib Dem members (19%) had canvassed voters face-to-face or over the phone than any other party.

Professor Bale said there was “all sorts of research over time that, certainly in very close races, contact with the voters, whether that be face to face or just leafletting does seem to make a difference”.

A Liberal Democrat spokesman said: “We have a record number of MPs, the most popular party leader in the country, and elected more councillors than Labour or the Conservatives for the first time ever in May’s local elections.

“When it comes to actual elections, more and more people are backing the Liberal Democrats as the only party that can stop Reform turning Trump’s America into Farage’s Britain.”