SEVENTY-five charities and campaign groups have criticised a Bournemouth MP after he complained about an Oxfam advertising campaign.

They signed a letter to The Times accusing Bournemouth West MP Conor Burns of attempting to “stifle” them.

But Mr Burns has claimed the signatories were largely Labour supporters and that they were engaged in a “diversionary tactic of the left”.

Mr Burns complained recently to the chairman of the Charity Commission about a Twitter campaign in which Oxfam targeted government austerity measures.

The film poster-style ad showed a raging sea with the slogan “The perfect storm... starring zero hours contracts, high prices, benefits cuts, unemployment, childcare costs.”

In The Times letter, the 75 signatories – including representatives of the National Federation of Women’s Institutes, Christian Aid, Friends of the Earth and the Ramblers – said Mr Burns’ intervention was “an attempt to stifle charities and campaign groups taking part in public debate”.

But Mr Burns said: “That’s a classic diversionary tactic of the left to accuse me of wanting to stifle free speech when I’m well known as one of the leading opponents of press regulation. I believe vibrantly in freedom of speech.”

He pointed to a post by the conservative blogger Guido Fawkes, who said many of those opposing Mr Burns had connections with the Labour Party.

Mr Burns added: “I think most people know what we’re saying is true and these people are defending their own vested interests.”

He accepted there was poverty in the UK but added: “Any reasonable person would also accept that the conditions of the poor in Britain are not even comparable to the conditions of the poor in Africa, which most people think Oxfam are there to work on.”

He said of the letter: “I think it was an attempt at a bully-boy operation to say ‘Don’t take us on’.”

The authors of the letter said they were also concerned that the government’s Lobbying Act would restrict their ability to speak out on public policy for seven months ahead of an election. They said campaigning organisations had previously persuaded reluctant governments to “cancel poor countries’ debts, remove lead from petrol, prevent the selling of our forests and allow Gurkha veterans the right of residence in the UK