A Conservative MP, who was a staunch opponent of equal marriage, is denying allegations of benefit fraud relating to his mother-in-law.

Peter Bone, 61, tweeted: “The Times allegation: We have done nothing wrong. The claims made are without foundation.”

According to The Times, questions were asked about whether Northampton County Council had been given accurate information about Dorothy Sweeney’s assets before paying out benefits totalling around £100,000.

Anyone with assets of more than £23,250 is expected to pay their own care home fees.

A case file has now been sent to the Crown Prosecution Service (CPS), whose special crime division is considering whether to approve charges.

There is no suggestion that Mr Bone’s mother-in-law has acted improperly. Mr Bone strenuously denies the allegations.

Northamptonshire Police said yesterday: “A 61-year-old man was formally interviewed under caution in April 2013 in connection with alleged fraud offences. A police file was submitted to the Crown Prosecution Service in November 2013 and we await their decision.”

Peter Bone is known for being an outspoken critic of equal marriage.

Mr Bone suggested in March 2012 that the Church of England should respond to the reform by saying: “marriage is between a man and a woman so this is completely nuts”.

Speaking to PinkNews.co.uk in November 2013, Mr Bone said this had been a reference to the political implementation of the policy rather than the actual principle of marriage rights for same-sex couples.

The Wellingborough MP unsuccessfully tabled a private member’s bill, which had called for a referendum on England and Wales’ same-sex marriage law.

In 1995, the Daily Mirror famously dubbed Mr Bone, who opposed minimum wage regulations brought in by Labour, the “meanest boss” in the country for paying a 17-year-old 87p an hour.

The MP said he would not have been able to hire her had a minimum wage law been in place and predicted at the time that such a rule would leave “hundreds of thousands” of people “condemned to the dole queue”.

Mr Bone voted against the Equality Act in 2007.