Image copyright PA Image caption David Cameron and his wife Samantha were shown props and backdrops from the Game of Thrones TV series during their visit to Belfast

Prime Minister David Cameron has visited the set of the hit US TV drama Game of Thrones during a pre-election visit to Northern Ireland.

His trip to Belfast is part of a 24-hour tour of each part of the UK.

Earlier on Tuesday, the Conservative leader visited Scotland. He will later fly to Wales and will end the day with an election rally in Cornwall.

Labour have criticised the visit and accused the government of "disengagement" from Northern Ireland.

Ivan Lewis, the party's shadow Northern Ireland secretary, said the visit came at a time when political stability in Northern Ireland was "hanging by a thread".

'Concerned'

Earlier, Mr Cameron told journalists he is a fan of Game of Thrones, which is partly filmed in Belfast's Titanic Quarter.

The show is one of the biggest success stories in Northern Ireland's growing film and TV industry.

The set is based in a former Harland and Wolff shipyard paint hall that has now been transformed into a TV studio.

Image copyright AP Image caption The Camerons got a close look at some of the weapons used in the many power struggles that take place in the popular TV series

After his tour, Mr Cameron said he had come to Northern Ireland "because the Conservative Party is the only party to stand in all four nations of the United Kingdom and I want to support my Conservative candidates".

He said he was campaigning for an all-out Conservative majority in May's general election.

Mr Cameron also said he was "concerned" about current disagreements over the Stormont House Agreement - the deal reached by Northern Ireland's five main political parties at the end of last year.

Media playback is unsupported on your device Media caption David Cameron said there was only 30 days left to the election and to the "threat of an Ed Miliband government"

The deal has since been threatened by a row over the cost of implementing welfare reform.

He said the five parties and Northern Ireland Secretary of State Theresa Villiers were "working hard" to reach a solution.

"We're clear about what can and can't be done," the prime minister said.

"We can't have the rest of the United Kingdom supporting a welfare system and paying for a welfare system that we don't have in the rest of the United Kingdom, but we want to keep the deal going.

"We're convinced that it can be done and we can continue with good devolved government here in Northern Ireland," he added.

Image caption David Cameron arrived in Northern Ireland on Tuesday morning as part of a 24-hour tour of each part of the UK

Mr Cameron's visit to the Game of Thrones set took in locations from the show, including the White Wall, the Sept of Baelor and the Armory, where he and his wife Samantha were shown some of the props used as weapons by the actors.

As he was given a tour, the prime minister said he was "fully up-to-date" with the latest series of the TV show.

As well as his visit to the TV studio, Mr Cameron's Belfast visit also included a meeting Conservative party members and activists.