NICOLA Sturgeon has poured scorn on Boris Johnson’s plan for a £20bn bridge between Scotland and Northern Ireland.

The First Minister compared it to the Prime Minister’s abandoned Garden Bridge over the Thames when he was mayor of London, which ended up costing taxpayers £43m.

The proposed Irish sea connection “would not be the first bridge that Boris Johnson has promised and failed to deliver”, she said.

Downing Street confirmed on Monday that UK Government officials were undertaking “a serious piece of work” on the Prime Minister’s hobby-horse, which he first floated in 2018.

The 25-mile link could connect Portpatrick and Larne as part of Mr Johnson’s plan to use big infrastructure projects to cement the Union.

However it would have to straddle Beaufort’s Dyke, a deep-water trench used to dump around a million tons of munitions, including 14,500 tons of chemical weapons.

Two years ago, Mr Johnson claimed: “The problem is not the undersea Beaufort’s Dyke or lack of funds. The problem is an absence of political will.”

But Sturgeon was distinctly sceptical when asked about the idea this afternoon.

Speaking at a Green Alliance event about the COP26 UN climate conference in Glasgow this year, she said: “I’m really ambitious for Scotland and its connections with our closest neighbours and the rest of the world.

“To say there are some big questions around the feasibility and the deliverability of the suggested bridge between Scotland to Northern Ireland would be an understatement.

“I mean, far be for me to point out this would not be the first bridge that Boris Johnson has promised and failed to deliver. So he has something of a track record.

“Look, if he wants to prove that it can be done and it’s feasible and deliverable then, you know, let’s see where he gets to.

“But this is deep water with a munitions dump at the bottom of it.

“I think there are some big questions. I guess if I was saying to him, Look if you’ve got £20bn available to build a bridge, I’m pretty sure me and I’m sure equally the First Minister of Northern Ireland could find lots of things to spend that on right now that actually would be really useful in accelerating the progress to net-zero [carbon emissions]

“I’m happy to take the twenty billion, Boris, but maybe not spend it on your latest bridge.”`