Luciana Berger has said that MPs are being “held hostage” in their parties and that she “looks forward” to more defections to the Liberal Democrats.

The former Labour MP, who quit the party in September to join the Lib Dems, said her former party had become “institutionally anti-Semitic” and that both Labour and the Tories are moving in more extreme directions.

Ms Berger accused Labour of trying to brush claims of anti-Semitism “under the carpet”, saying people should be under “no illusions about what festers in the British Labour Party”.

Speaking at a fringe event at the Lib Dem conference in Bournemouth, Ms Berger said: “Of course MPs are considering their positions, do their parties still reflect the values that led them to join in the first place?”

She added: “We are seeing people essentially being held hostage in their parties, because I certainly know there are MPs of all colours that are really struggling with what they see happen and the decisions that are taken by their leaderships.

“I can’t tell you for sure but I look forward to more colleagues joining us in the future.”

Ms Berger spoke of her disappointment with how the Labour Party has responded to accusations of anti-Semitism within the party.

She said: “I left the party because, in my view, it has become institutionally anti-Semitic and because of its position on Brexit.”

She told the Lib Dem conference she had tried to fix problems in the party “from within”, but that they had only got worse.

She said: “They are now subject to a statutory investigation by the Equalities and Human Rights Commission.

“This is not the BNP that was previously investigated. This is Her Majesty’s Opposition. And any party in that situation should be appalled.

“They have sought to basically, like, brush it under the carpet, they have not admitted where they are at.”

She added: “Let’s not be under any allusion about what festers, sadly, in the British Labour Party today.”