A Welsh Assembly minister has resigned after a series of gaffes including walking into a pub smoking a cigar.

Former Heritage Minister Rhodri Glyn Thomas said in his resignation letter that his position was "no longer sustainable" because of the publicity that had followed him during the past few weeks.

The Plaid Cymru member had been asked to leave a pub in the country's capital, Cardiff, when he walked up to the bar with a lit cigar in his hand last Wednesday.

He had previously been a keen advocate of the ban on smoking in public places ahead of its introduction in Wales in April 2007.

The Carmarthen East and Dinefwr AM had also been criticised earlier this month when he mistakenly read out the wrong name when announcing the winner of a literary award.

The minister, who had been responsible for policy on culture, sport and the Welsh language in the one-year-old Assembly coalition between his party and Labour, said in his resignation letter: "In the light of the publicity that has been following me in the last weeks I feel that my position in the government is no longer sustainable.

"Further comments would be bound to follow."

His resignation was accepted by First Minister Rhodri Morgan, who thanked him for his work during the past year especially on preparing forthcoming legislation on the Welsh language and work on the Millennium Centre.