Jacqui Smith faces political ruin as a result of the damning verdict that a Commons watchdog passed on her expenses claims and because police support officers contradicted her account of her movements.

The former Home Secretary offered a grudging apology to the Commons yesterday after the Parliamentary Commissioner for Standards ruled that she was wrong to nominate her West Midlands property, where her family lives, as her second home.

Ms Smith said that the report vindicated her claim that she spent substantial amounts of time in a house in London owned by her sister, which she designated as her main home.

But John Lyon revealed that police guarding the property questioned the veracity of the former Home Secretary’s evidence, with their records showing that the number of nights she had spent in London was at odds with Ms Smith’s account. He says that last year the police figures suggested that Ms Smith spent 37 more nights in Redditch than she had in London; her estimates based on her diary suggested that the difference was nine nights. Figures for the previous year suggest that she had spent 12 more nights in Redditch than in London.

According to a test used by Commons officials, MPs should classify as their main residence the home where they spent most nights.

Ms Smith told the Commons that in retrospect the decision to designate her sister’s property as her main residence was wrong and she apologised. She also apologised for claiming the cost of adult films. Mr Lyon found that she had overclaimed by a further £185, of which £20 was for entertainment items as part of her cable TV and internet subscription.

The report is highly embarrassing for Ms Smith and could increase the chances of her standing down from her highly marginal Redditch constituency before the general election. She said nothing about her political future yesterday, although her local Labour Party insisted that she intended to stand again.

MPs on the cross-party Standards and Privileges Committee decided not to make her pay back any money, however, saying that it was impossible to quantify the financial implications of her decision or say “with any certainty whether the taxpayer is any worse or better off as a result”.

Ms Smith claimed at least £116,000 in second-home allowances over the period examined.

Mr Lyon concluded that, between June 28, 2007, and March 31, 2009, she spent more nights at her Redditch home than at the London property.

He added: “Ms Smith did not give sufficient weight either to the objective overnights test or to the need to consider whether she was an exception to the rule.” He added that this was “not in accordance with the rules of the House at the time”.

He continued: “In my judgment, Ms Smith misdirected herself by focusing on the nature and location of her job (where she spent her long working day) and not the nature and location of her overnight accommodation (where she went whenever her working life allowed).”

The former Home Secretary and her aides responded by attacking Mr Lyon. She said that his report “appeared to be heavily influenced by subjective judgments” and that she had followed the advice of the Commons Fees Office at all times.

She added: “I am disappointed that this process has not led to a fairer set of conclusions, based on objective and consistent application of the rules as they were at the time.”

In her West Midlands constituency last night, Ms Smith’s political opponents were preparing to overturn at the next general election her slim majority of just 1,948.

Juliet Brunner, a Tory councillor on Redditch Council, said: “I was at a residents’ meeting today where the expenses scandal came up. People were very angry. They were saying that they were absolutely disgusted.”

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