MSPs have warned that the £776 million share of EU funding which Scotland gets from Brussels must not be cut when a post-Brexit UK-only replacement is introduced.
There is growing "concern and uncertainty" about the proposed new UK Shared Prosperity Fund (UKSPF) amid consultation delays, according to Holyrood's Finance and Constituion committee.
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They are now calling for UK and Scottish Government to address the concerns which could leave current recipients of EU Structural Funds (EUSFs) in the lurch.
Committee convener Bruce Crawford said: “We agree with the evidence we received, and with the Scottish Government, that Scotland should receive from the UKSPF no less than its current allocation under existing programmes.
"There should be no regression in funding given regional disparities across the UK have not reduced."
The current structural funds programme is worth about €10.7 (£9.5) billion to the United Kingdom and up to €872 (£776) million to Scotland across the seven-year budget period which ends in 2020.
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After 2020 the UK Government is planning to operate a domestic replacement fund - the UKSPF. A UK Government public consultation on the policy had been expected to take place before the end of 2018 - but is now scheduled for 2020.
“EU structural funds are a valued source of support for communities across Scotland especially in rural areas," Mr Crawford added.
"We welcome the intention to replace those funds should the UK leave the EU but are concerned at the delay in the consultation on the UKSPF.
“This is causing concern and uncertainty for those currently in receipt of EUSF. It also impacts on transition planning by current EUSF recipients as well as pre-application planning by potential new recipients.
“We have asked both the UK and Scottish Governments to confirm how they will address these concerns.”