The number of Liberal Democrat party members has almost halved in the last five years, according to BBC analysis of available figures.

The figure has fallen 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 spokesperson said “in actual elections, more and more people are backing the Liberal Democrats”.

It comes as the Green Party of England and Wales says it now has 90,000 members, a 91% increase on 2020 figures.

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. However, it does not provide a breakdown.

Prof Tim Bale leads the Party Membership Project, a joint project between Queen Mary University of London and Sussex University.

He 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.”

In more positive news for the Lib Dems, he said research carried out by his project after the 2024 election showed that the Liberal Democrats were the most active of all the memberships of the political parties.

Figures collected showed that a greater proportion of Lib Dem members (19%) had canvassed voters face-to-face or over the phone than any other party.

Prof 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 spokesperson 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.”

Working out how many members a political party has can be tricky.

There is no legal obligation for political parties to publish their membership figures, so they tend to only be revealed in annual accounts or when a party holds a leadership election.

Labour, which is the largest political party in the UK on current publicly available figures, has seen a drop in membership of 37% since 2020.

Latest published figures put its membership at 333,235 at the end of last year, although reports have suggested it may have fallen further to 309,000.

An updated figure should be given by Labour later this month, when the winner of its deputy leadership contest is announced.

Reform UK did not give a figure for membership in its annual accounts last year, but a ticker on its website says it has just under 260,000 members.

The Green Party of England and Wales has seen a rapid surge in membership and now says its has 90,000 members, which is a 54% rise on last year’s figure of 58,322 in December.

The Conservatives do not routinely publish their membership figures, but 131,680 people were eligible to vote in last year’s Tory leadership election, which is 40,000 fewer than in the 2022 contest.

Party membership figures are not verified by outside bodies.

The figure that has been most recently used for the current size of the Lib Dems is 83,174, which was the figure for December 2024 that appears in the party’s annual accounts, including both members and registered supporters.

As the freelance journalist Adam Ramsay has pointed out, the figure for paid-up members is given elsewhere, in a statement for the party treasurer in the accounts for the Liberal Democrats in England.

It says there was an “overall membership of 60K”, with 55,000 – or 92% of them – in England, and supporter levels that “remain constant at over 20K”.

To get the membership figure for 2020, we looked to the number of ballot papers issued in the leadership election, as only full members can vote.

At the time, the party said it had issued 117,924, papers, which was its highest ever number.