Famous alumni of Scotland's national youth theatre have expressed their shock and dismay after it lost its regular funding from the national arts agency.

Actors including John Michie, Colin McCredie and Kirstie Steele have voiced their concern after the failure of Glasgow-based Scottish Youth Theatre (SYT) to land a crucial three-year funding deal from Creative Scotland.

The company (SYT) has now also received strong support from Culture Secretary Fiona Hyslop, who said the Scottish Government "strongly believes" in its work.

Mr Michie, a patron of the company and actor known for his appearances in Holby City, Taggart and Coronation Street, said: "When joining SYT as a patron earlier this year, I was so struck by their enthusiasm skills and sheer range of ambition.

"Their young people give so much to Scotland and I cannot think where Creative Scotland's funding decision can have come from."

Ms Steele said that SYT had been a "driving force" of his acting ambitions, and that he hoped alternative funding could be found.

Mary McClusky, artistic ­director and chief executive of SYT, said the decision to not give regular funding to the company was "unfathomable", and that it has received high-profile support from former actors and supporters on social media.

John Scott Moncrieff, chairman of SYT, said the group had been extremely disappointed by the decision, made as Creative Scotland unveiled its portfolio of companies backed by £100 million in funds last week.

Last night Creative Scotland said it highly valued the work of the company, which it is giving £220,925 this year, and would discuss its future in the coming days and weeks.

Other Creative Scotland funds the group can access include the two-year Open Fund and Targeted Funding.

SYT, which works in schools and arts centres across Scotland and whose alumni include Karen Gillan, Gerard Butler and KT Tunstall, said it was aware there might be future funding from other sources of income available with Creative Scotland, and would be meeting with Ms Hyslop next week.

The Culture Secretary, who is not involved in Creative Scotland funding decisions, as it is an arm's-length body, said: "We strongly, as a government, believe in the importance of having the national youth theatre provision for Scotland, and how we do that and how it is supported needs to involve a discussion between SYT and Creative Scotland and I know initial meetings have already taken place."

Frank McAveety, the former culture minister and Glasgow councillor, said "the decision to withdraw their funding is a sad day for Scotland".

Creative Scotland's cash for the organisation amounted to about 25 per cent of its total funding - it raises about 52 per cent of its income and says it is working towards "a more sustainable financial model".

It gives classes and courses in Glasgow, Edinburgh and Aberdeen as well as a Summer Festival course, and its National Roadshow is a three-year programme of free drama workshops that are available in secondary schools and community youth groups.

Ms McCluskey added: "It's great that Creative Scotland are talking about other funding options being available. But at the moment it is just talk.

"We're looking forward to having a meaningful conversation that will give us more detail and certainty about the company's future.

"The shock and support that our participants, parents, alumni and the arts community have expressed on social media has been heartening and encouraging and is proof of the huge impact that our activities have."