LIBDEM leader Jo Swinson has said her party will launch legal action if ITV does not include her in its televised leaders' debate.

The party has already complained to ITV about Swinson's exclusion from an election debate between Boris Johnson and Jeremy Corbyn.

Swinson leads the fourth largest party in the Commons with 19 MPs - with only 12 of those elected as LibDem MPs in 2017.

The SNP is the third largest party in the Commons with 35 MPs and also the second largest party in terms of membership across the UK.

The MP for East Dunbartonshire said debates about who will be the next prime minister "cannot and should not exclude the only woman leader who is able to be the next prime minister".

About 90 minutes after Swinson spoke to the media, it emerged that Sky News is proposing a live TV debate between Johnson, Corbyn and Swinson on Thursday November 28.

Swinson said the LibDems are taking advice on "all of the possible avenues" and "do not rule any out".

READ MORE: Corbyn, Johnson and Swinson invited to Sky News TV debate

Speaking to reporters outside Parliament today, Swinson said: "As Liberal Democrats we will take any action required to make sure that that voice of Remain is represented in those debates.

"We are taking legal advice and we will pursue legal avenues if ITV do not change their format.

"Because it is so important that millions of Remainers can make sure their voice is represented, that it is a fair debate between the different options on offer, and that for the girls and young women across our country they see that women can be political leaders and prime ministers too."

A spokeswoman for the party said a legal team has been instructed to be prepared to launch legal action if ITV does not change its decision "quickly".

Swinson said they have had meetings with ITV, adding: "We will be following up with letters and legal action, and we will of course keep you informed about those steps as those actions progress."

READ MORE: Election: Jo Swinson calls to be included in 'three-way' TV debates

ITV has said it was already scheduling a separate live debate to include seven party leaders, as well as the head-to-head.

And the broadcaster said Swinson and other party leaders have been invited to take part in a live interview programme later on, during the night of the Corbyn-Johnson debate.

An ITV spokesman said at the weekend: "ITV intends to offer viewers comprehensive and fairly-balanced General Election coverage.

"This involves a wide range of programming, including a live debate programme in which seven party leaders are invited to take part, as well as a live debate between the Labour and Conservative leaders."