HOLYROOD would require an extra 70 MSPs to cope with the extra workload if Scotland became independent, a senior SNP backbencher has claimed.

Dave Thompson, the convener of the parliament's standards committee, said extra MSPs would be required for committees dealing with new areas of responsibility, such as welfare and foreign affairs, if Scotland votes Yes.

He also said the Scottish Government would need a substantially enlarged cabinet.

He suggested the total should rise from 129 MSPs to 199, with each of the 70 mainland constituencies returning two members.

Mr Thompson, MSP for Skye, Lochaber and Badenoch, put the cost of adding 70 MSPs at £4 million but claimed an independent Scotland would save £12.5m by no longer sending MPs and peers to Westminster.

The transition plan for independence, published on Tuesday, made no mention of possible changes to Holyrood to reflect the additional powers and workload of a fully sovereign parliament.

Opposition MSPs warned the £400m Holyrood complex would have to be extended to accommodate more members.

Scottish Labour's James Kelly MSP, said: "If Dave Thompson wants another 70 MSPs, he will need to explain where he wants to put them. Is he suggesting that we build a bigger Parliament?"

Scottish Conservative MSP Alex Johnstone said: "We know Alex Salmond doesn't like scrutiny or transparency, so perhaps he'd get rid of the media gallery to cram them in."

A Scottish Government spokeswoman said: "The Scottish Government has no such plans – the independent Scottish Parliament which will be elected in May 2016 in the event of a Yes vote will comprise 129 members, as at present."