SCOTLAND'S Finance Secretary Derek Mackay has urged UK Chancellor Philip Hammond to provide more clarity on Brexit, including future EU funding.

Mackay has written to Hammond ahead of the UK Government's Spring Statement to address economic and fiscal forecasts.

He wrote: "It is imperative that the UK Government urgently provides details of how it plans to mitigate the significant impacts of leaving the EU and how the £3 billion funding for EU exit preparations which was announced at last year's Autumn Budget will be allocated. Scotland must have its fair share of this funding.

"The people of Scotland voted overwhelmingly to remain in the EU and the Scottish Government firmly believes that Scotland's public finances should not bear the costs of EU exit.

"We have been absolutely clear that Scotland must not be any worse-off in respect of the funding allocations that replace those provided from the EU and that they must be focused on delivering inclusive growth."

He urged Hammond to give people and business more certainty on the process of leaving the EU, and to "engage meaningfully" with the Scottish Government on Brexit impacts.

Scottish Government analysis indicates a "no deal" Brexit will cut Scottish economic growth by 8.5 per cent by 2030 while leaked draft UK Government document predicts an even steeper 9 per cent drop.

Mackay repeated calls for the UK Government to end unnecessary austerity and to clarify its position on public-sector pay.

He reiterated a demand for a backdated VAT refund for police and fire services in Scotland.

A Treasury spokesman said the department would not comment on the content of the Spring Statement in advance of delivery on Tuesday.