LABOUR last night added its voice to the row over the head of the umbrella group for Scotland's charities and the independence debate, demanding the organisation open itself up to scrutiny.

The intervention came amid renewed criticism of Martin Sime, the chief executive of the Scottish Council for Voluntary Organisations (SCVO), who has been accused of being too close to the SNP government, and of trying to engineer support for a second question in the 2014 referendum.

The Herald yesterday revealed that Mr Sime was the direct beneficiary of a £10,000 SNP government grant to the SCVO, which enabled him to take a six-month globe-trotting sabbatical in 2008-09.

The money was put towards Mr Sime's accommodation and visits to the USA, Canada, Africa, India, Australia and New Zealand.

The SCVO insists Mr Sime produced a report on his return, but last night said he was too busy to find a copy when the Herald asked for one.

Last week, the Herald revealed Mr Sime and Alex Salmond's special adviser on the constitution had corresponded by email about a second question on more powers for Holyrood, a useful fallback for the SNP if voters reject independence.

The disclosure led Willie Rennie, leader of the Scottish LibDems, to demand that Mr Sime resign.

In a sign of growing cross-party concern, Labour MSP Patricia Ferguson said: "The SCVO and a range of other civic organisations have an important part to play in shaping the debate over our country's future but they must also accept that scrutiny comes with that responsibility."