THERESA May is under pressure to explain why she did not turn up “for her day job” and attend the British Irish Council summit.

The UK prime Minister did not join other leaders at the gathering, despite crucial issues on Brexit, devolution and the Irish border dominating the agenda.

Taoiseach Leo Varadkar was at the meeting on Guernsey, as was First Minister Nicola Sturgeon and Welsh First Minister Carwyn Jones. But the most senior member of the UK Government to attend was David Lidington, the Cabinet Office Minister and May’s de facto deputy.

A senior Scottish Government source told The National that May’s refusal to show up for the key summit showed a “lack of respect” for the other partners, and has been a major issue for a long time.

“Given the meetings require participation from each delegation, it also shows a lack of confidence in the message she would bring – particularly about Brexit,” the source told us.

The British Irish Council is a key institution set up as part of the Good Friday Agreement to foster positive relations among the governments of the British Isles and to advance the peace process in Northern Ireland.

Tony Blair was the last UK Prime Minister to attend a Council summit, 15 years ago. The Irish Government has been represented every year since 1999 by its head, the Taoiseach.

No Conservative Prime Minister has ever attended, according to the communiques published by the body.

Deidre Brock, the SNP’s Northern Ireland spokeswoman, called on May to explain why she did not turn up.

Brock said: “What on Earth is Theresa May thinking? The UK is in the middle of a huge constitutional change and the Irish border is one of the biggest issues in that. For the Prime Minister of the UK to be posted missing at such a crucial time is incredible.

“It’s bad enough that Gordon Brown and David Cameron didn’t go but it’s a dereliction of duty for this Prime Minister to dodge the difficult Brexit meetings where there are real issues to be thrashed out about what Brexit really means.”

Brock added: “The UK leaving the EU – being dragged out in Scotland’s case – has profound implications for everyone on these islands but the possible repercussions are even more serious for communities along the Irish border and in Northern Ireland. This is a place still sorting out the legacy of its recent history and still grappling with the economic effects of that history.

“It’s a place that needs support and the proper consideration of politicians and Mrs May has failed that test. The Taoiseach manages to get to these meetings in spite of his heavy workload. He’s there now for the discussions on Brexit and the situation in Stormont.

“Scotland and Wales’s First Ministers are there – they’ve turned up for work, they’re doing the day job. It’s shameful the Prime Minister doesn’t think she needs to bother.”

The First Minister was joined at

the summit by Brexit Minister Mike Russell and Environment Secretary Roseanna Cunningham.

After Sturgeon and Varadkar held bilateral talks, the First Minister posted a picture of them on Twitter and said: “Discussions on shared interests and continued cooperation, including concerns in light of #Brexit, between FM @NicolaSturgeon & Ireland’s Taoiseach @campaignforleo while at #BICGuernsey.”

A UK Government spokesman said it had “very senior representation” in the shape of Lidington, Northern Ireland Secretary Karen Bradley and Brexit Minister Robin Walker.