THE Scottish Government is facing fresh pressure to upgrade the A1 north of the Border after it emerged Westminster is set to remove the last remaining single carriageway sections in England.

The UK Government is poised to give the go-ahead to upgrade the road between Newcastle and Berwick as part of a multi-billion-pound infrastructure programme.

The move is expected to be included in Chancellor George Osborne's spending review in June, and yesterday sparked renewed calls to improve the route in Scotland.

Despite being one of Britain's main north-south routes, the A1 still has several sections of single carriageway on either side of the Border, which campaigners claim cause delays and reduce safety.

Of the 47 miles of the A1 between the Border and Edinburgh, 30 miles are dual carriageway.

Scottish Conservative MSP John Lamont, whose Ettrick, Roxburgh and Berwickshire constituency includes a section of the A1, said: "The Coalition is holding up its end of the bargain after making the A1 a route of strategic importance.

"It's time now for Alex Salmond to do the same thing.

"Just because the road leads to England is not a good enough reason for the SNP to refuse to find the money to upgrade it.

"With improvements being made south of the Border, the risk is you will have increased traffic coming to Berwick-upon-Tweed, then experiencing a massively poorer quality of road for a crucial section leading to Edinburgh."

Last December, East Lothian and Scottish Borders councils called on the Scottish Government to dual the A1 from Dunbar to the Edinburgh ring road.

Both councils argued the improvements would help boost the local economy. East Lothian and Edinburgh councils, rather than the Scottish Government, are responsible for the northern-most three miles of the road.

Details emerged yesterday of a number of major road improvements set for approval by the UK Government.

It is understood the Chancellor is prepared to underwrite a £1 bil-lion new toll road in south Wales to ease congestion on the busy M4. Other projects include dualling the A303 in south-west England and upgrading the A47 through Norfolk.

The SNP Government has long prioritised upgrading the A9, the main road to the Highlands, to dual carriageway. The plan was an election manifesto pledge in 2007 but construction is not expected to start until 2017. The Government is committed to completing the project by 2025.

Ministers have also promised to dual the A96 between Inverness and Aberdeen by 2030.

The Scottish Government's Transport Scotland agency said there were no current plans to dual the A1 north of the Border.

A spokesman said: "Since 2007, more than £300 million has been spent to maintain and improve key routes in the south-east, including the A1, the majority of which in Scotland is already dual carriageway.

"Our analysis shows the route enjoys a safe and efficient operation and experiences few journey time reliability issues. As such, the key objective for the route is to promote a continuing reduction in accident rates and with this in mind we will continue to look at ways to improve and upgrade the A1."