AFP • GETTY The proposals formed the centrepiece of the First Minister's programme for government

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The proposals formed the centrepiece of the First Minister's programme for government in a move designed to boost the economy. But opposition MSPs said the policy had been "cobbled together" after it was confirmed Whitehall, which will have to give approval, was not consulted. Under the Scottish Growth Scheme the SNP administration will provide a "guarantee" for up to £500million of lending to small and medium businesses. The package will also include some Scottish Government loans, which may be issued on their own or alongside the guarantees.

It is meant to help firms invest and expand when financial institutions are reluctant to lend because of uncertainty caused by Brexit. However, the taxpayers would then foot the bill if the firm is unable to repay the money. Ms Sturgeon told MSPs on Tuesday she hoped to win the backing of the UK Treasury, as it involves part of the Scottish budget that MSPs have no discretion over spending. But today Finance Secretary Derek Mackay revealed there had not even been informal talks with London before making the announcement.

He told Holyrood's finance committee: "We had no conversations with them on this specifically before bringing it to parliament. We gave parliament the courtesy of knowing first. "I have writen to the Chief Secretary to the Treasury, and I hope the UK Treasury will be co-operative around this, because it has no financial call upon the UK Government, but if delivered could be of great assistance to the business community in Scotland and be managed by the Scottish Government." He was challenged by Tory MSP Murdo Fraser who said: "Surely you should have had at least a conversation with them in advance to try ad understand whether support would be forthcoming, before announcing it with such fanfare."

GETTY Finance Secretary Derek Mackay revealed there had not even been informal talks with London

But Mr Mackay replied: "Murdo Fraser is well aware that the UK Government often makes decisions that impact on Scotland our budget and our businesses without engaging with the Scottish Government first."

We had no conversations with them on this specifically before bringing it to parliament Finance Secretary Derek Mackay

"I see no good reason why the UK Government wouldn't want to proceed with this and support us on this. In fact I wouldn't be surprised if they copy it." Relations between the Treasury and Scottish ministers reached a new low last year amid a lengthy stand-off over the "fiscal framework", underpinning Holyrood's new tax and welfare powers. A Whitehall source said: "In the old days when you had the same colours of government, there is no way you would announce something like this without clearing it with the Treasury.

Sturgeon's top moments Fri, December 9, 2016 Scotland's First Minister Nicola Sturgeon in pictures. Play slideshow Getty Images 1 of 33 Nicola Sturgeon visits Glaxo Smith Kline.

PA Ms Sturgeon told MSPs on Tuesday she hoped to win the backing of the UK Treasury