HOME Secretary Jacqui Smith is facing a parliamentary “sleaze” investigation over her second home allowance.

It emerged that the Parliamentary Commissioner for Standards, John Lyon, has written to Ms Smith calling on her to explain the £116,000 which she has claimed since becoming an MP.

Ms Smith insisted she has done nothing wrong and said she was “very happy” to answer the commissioner’s questions.

Mr Lyon had previously rejected two complaints into her decision to designate her sister’s house in south-east London – where she stays when she is in the capital – as her main home.

The move has enabled her to collect at least £116,000 over the years in second home allowances on her constituency home in Redditch, Worcestershire, where her family live.

It is understood that the latest complaint was submitted by two of her London neighbours, Dominic and Jessica Taplin, who are challenging her claims over the amount of time she spent there.

A spokesman for Mr Lyon said: “He has accepted a complaint against Jacqui Smith and is following the procedure laid down for him.”

Mrs Taplin was quoted in The Mail on Sunday as describing Ms Smith’s claim that she spent most of the week there as a “fabrication”.

The couple claimed that often she was there for just two days a week and rarely spent Sunday nights there.

Ms Smith insisted today that her accommodation arrangements were fully in line with Commons rules.

She said: “I sought advice about the arrangements that I make for living in two places like lots of MPs have to.

“I followed the advice that I was given and I followed the rules. And therefore I’m very happy to answer further questions that the independent commissioner puts to me.”

Ms Smith was said to be confident she could refute the allegations made by Mr and Mrs Taplin, insisting there were “factual inaccuracies” in their account to The Mail on Sunday.

There was some anger within Labour circles at the apparent role of the Tories in the affair.

Conservative sources confirmed that Mrs Taplin had sent an email last week to the office of party leader David Cameron outlining her concerns.

The sources said the email was not read by Mr Cameron, although a party official did suggest that she might want to contact a newspaper as a matter of “public interest”.

Mr Cameron said he believed there were questions for Ms Smith to answer about her second home arrangements.