The SNP has suffered an embarrassing defeat at the hands of one of its own former MSPs who rejected the party's praise of the Finance Secretary's budget, opposition parties say.

Jean Urquhart vetoed an SNP bid to steer Holyrood's Finance Committee to support John Swinney's 2013/14 draft budget.

The SNP motion said Mr Swinney's budget plan "encourages sustainable growth", but Ms Urquhart voted with Tory and Labour MSPs to reject it.

Ms Urquhart resigned from the party in October alongside fellow SNP rebel John Finnie over the party's new support for Nato, reducing the SNP's parliamentary majority to one.

The resignations shifted the balance of power on three Holyrood committees, with the SNP now in a minority on the finance, justice and equal opportunities committees.

Labour Finance Committee member Michael McMahon accused the SNP members, which include convener Kenneth Gibson and vice-convener John Mason, of drafting a motion that was at odds with the evidence.

"The SNP Government tried to prevent any real scrutiny of its budget by failing to give us sufficient detail and ordering its majority of backbenchers to block any attempts to get to the bottom of this," he said.

"Despite these efforts, the Finance Committee couldn't find any real evidence to sustain the Scottish Government's assertion that this is a budget for growth.

"On the contrary, witness after witness argued the opposite and it seems only those under the SNP whip believe this set of spending priorities is about creating jobs."

Conservative member Gavin Brown said Ms Urquhart's scepticism had led to an "embarrassing defeat" for the SNP.

"The SNP's budget started to unravel the day after it was delivered. That unravelling shows no sign of stopping," he said.

An SNP spokesman said: "This is a positive report for the Scottish Government. What the Tories failed to mention is that their own amendment – which said that this wasn't a budget for economic growth – was also rejected by the committee."