John Downie, director of public affairs at the SCVO, said in its publication Third Force News, which is run by his organisation, that charities should be concerned about whether politicians are attempting to use the regulator to silence criticism from voluntary sector organisations.
Downie was speaking after Conor Burns, the Conservative MP for Bournemouth West, asked the Charity Commission to investigate whether a tweet from Oxfam, which said that austerity was forcing more people into poverty, was politically motivated.
Downie said: "Rather than being concerned about charities campaigning on areas they have a complete right to campaign on – such as Oxfam on poverty – maybe we should be more concerned about the Charity Commission being used as a front for the government.
"Oxfam is completely correct to say that highlighting poverty should be non-party political.
"The only people playing politics here is the government, which is threatening the independence of the third sector because it doesn’t want attention drawn to issues such as poverty – where it has taken completely the wrong approach."
A group of more than 70 charities and campaigning groups recently expressed concern that the call by a Conservative MP for the Charity Commission to investigate a tweet by Oxfam was the "latest attempt to stifle charities and campaign groups taking part in public debate".
A spokeswoman for the Charity Commission declined to comment because it was still assessing the complaint about Oxfam.