A Liberal Democrat candidate has apologised after his party published an advert suggesting Plaid Cymru supported a "hard Brexit".

Elin Jones, the Plaid AM for Ceredigion, said the claim was untrue.

Mark Williams, who is seeking re-election as the constituency's MP, has since said the Facebook advert was "nonsense" and has been removed.

The Welsh Lib Dem leader added that his party was "working with all against hard Brexit, including Plaid Cymru".

In the Facebook advert, the Liberal Democrats said they were the only party "fighting to keep Britain in the single market at this election".

The advert went on to say that "Plaid Cymru are backing an extreme Brexit, along with Labour, the Tories and UKIP".

Image copyright Facebook Image caption The advert on Facebook was later removed

The Lib Dems have pledged to hold a second referendum at the end of the Brexit talks, with voters given the option of remaining in the EU if they do not like the outcome of the final negotiations.

Plaid Cymru has said it accepts the result of last year's referendum, but that the party would fight for a "good deal for Wales".

Ms Jones published the picture of the Lib Dem advert on her Facebook page on Monday, saying that "Plaid Cymru has not, does not, will not support an extreme Brexit".

"Everything we have said in this election makes that clear. And yet the Lib Dems lie and say otherwise here," she said.

Ms Jones added that she had "expected better" from Mr Williams, and demanded an apology.

Image caption Mark Williams said the advert was nonsense

In a later post on Twitter, she also said that Lib Dem leaflets with a similar message had been circulating in the constituency.

The leaflet read: "Plaid and Labour are in bed with the Tories and UKIP in an extreme Brexit deal".

Mr Williams apologised on Twitter for the social media material, saying: "Facebook advert was nonsense and has been removed.

"I value working with all against Hard Brexit, including Plaid Cymru, to whom I apologise."

Mr Williams has been the MP for Ceredigion since 2005, when he captured the seat from Plaid Cymru.

The Plaid Cymru candidate in Ceredigion in this year's election is Ben Lake.

Full list of candidates for Ceredigion