The government will review the wording in contracts and grant agreements so they do not prevent charities from criticising government policy, the Prime Minister has said.
In response to a letter from Sir Stuart Etherington, chief executive of the National Council for Voluntary Organisations, Theresa May said the government contracts included provisions "to ensure that providers adhere to the high standards we expect" and helped it to respond in circumstances such as a contractor breaking employment law or using unethical practices.
But she said she wanted to make it clear that these provisions were "in no way ‘gagging clauses’".
She said: "They do not stop providers or affiliates from fairly criticising government departments of government policy.
"Furthermore, they do not prevent charities from campaigning for any particular cause and would never be used as a means of attempting to stifle debate or prevent legitimate criticism."
May said she wanted to assure Etherington that the government would "consider ways of clarifying future contracts and grant agreements in order to address the unfortunate perception that has arisen regarding these clauses".
She added: "I maintain that it is vital that the sector’s independence and freedom of speech are protected to allow charities and social enterprises to continue providing a voice for everyday people."
Etherington wrote to the Prime Minister last month calling for clarity on the use of gagging clauses after The Times newspaper reported that as many as 40 charities had signed probation service contracts with the Ministry of Justice that said they could not do anything that would adversely affect the reputation of the justice secretary.
Etherington said today the letter would reassure charities working under such contracts but also sent a message more widely.
"A number of issues in recent years led some charities to ask whether the government simply didn't want to hear what they had to say," he said.
"This is a clear statement that the Prime Minister believes charities should be uninhibited in speaking out about the facts they're finding on the ground."