'Student politics' row over SNP arms funding policy
He said: "It really strikes me as student union politics. It's not a serious government concerned about the opportunities for young people in the future.
"It's not concerned about the skills base of Scotland or indeed the industry and innovation in the future because Scotland does have a big part to play in strengthening the industrial base as we will through more defence investment."
The UK government said Rolls Royce was planning to invest £11m in the welding project, and that it would step in to provide the £2.5m support grant if it was not funded by Scottish Enterprise.
The Scottish government refuses to provide funding to firms directly for the creation of arms, but does offer cash for other things, such as diversifying away from the munitions industry and apprenticeships.
Rural Affairs Secretary Mairi Gougeon said it was important to take a principled position.
She told the programme: "The project wasn't eligible for funding because of the long standing policy position that we have that we do not provide or support the use of public funding for the manufacture of munitions.
"I think the key difference between ourselves and the UK government is that, when we have principles, we stick to them."
She said the Scottish government recognised the unprecedented security threats, particularly in light of Russia's invasion of Ukraine.
But she added: "That doesn't mean that we can't also maintain the policy positions that we have had for quite a long time and have been long standing within our party, that we don't support the use of public finance for the manufacture of munitions and neither do we support that for nuclear weapons."
