Fiona Onasanya arrives at the Old Bailey

Shamed MP Fiona Onasanya will walk free from prison today after less than a month behind bars.

She was sentenced to three months in jail at the end of January for perverting the course of justice after lying about a speeding ticket, but it is understood she is being let out as part of an early-release scheme.

Onasanya, 35, a solicitor, is expected to be released from HMP Bronzefield in Surrey early this morning after only 28 days in custody.

The MP will be forced to wear an electronic tag and obey a curfew but will otherwise be at liberty. She could even come back to the House of Commons to speak – and vote – in the crunch Brexit debate tomorrow.

Labour has kicked Onasanya out of the party, but she has continued to collect her £77,000 salary while behind bars.

If she had been jailed for a year or more, she would have been forced to give up her Peterborough seat, but the three-month sentence means she will face a by-election only if 10 per cent of her constituents sign a ‘recall petition’.

She is also appealing against her conviction.

Calls for the sentence to be extended were dismissed yesterday after the Government’s most senior law officer decided it was not unduly lenient.

CCTV footage showing Fiona Onasanya speeding 41mph in a 30mph zone in the village of Thorney near Peterborough

Onasanya was jailed at the Old Bailey on January 29. The following day several complaints were received by the Attorney General’s Office that the sentence was too short

Onasanya was jailed at the Old Bailey on January 29. The following day several complaints were received by the Attorney General’s Office that the sentence was too short. But a spokesman for the Attorney General’s Office said: ‘After careful consideration, the Solicitor General has concluded that he could not refer this case to the Court of Appeal.

‘A referral under the Unduly Lenient Sentence scheme to the Court of Appeal can only be made if a sentence is not just lenient but unduly so, such that the sentencing judge made a gross error or imposed a sentence outside the range of sentences reasonably available in the circumstances of the offence.

‘The threshold is a high one, and the test was not met in this case.’

Festus Onasanya, Fiona's 33-year-old brother

If the sentence had been deemed to be unduly lenient, it would have been sent to the Court of Appeal for a decision on whether it should be increased.

Jurors in Onasanya’s trial heard that the MP colluded with her brother Festus, 34, after her car was clocked doing 41mph in a 30mph zone in the village of Thorney, near Peterborough, in July 2017.

The court was told she was sent a ‘Notice of Intended Prosecution’ to fill out, but it was sent back naming the guilty driver as Aleks Antipow, an acquaintance of her brother, who was visiting his parents in Russia at the time. Her brother received ten months in prison after he pleaded guilty to three counts of perverting the course of justice relating to speeding offences, including the July 24 incident.

At the trial, Mr Justice Stuart-Smith described Onasanya’s decision to deceive police as ‘disastrous’. He added: ‘You have not simply let yourself down; you have let down those who look to you for inspiration, your party, your profession and Parliament.’

He said the politician ‘stupidly’ chose to become embroiled in a scam hatched by her brother. The MP has refused to confirm that she was driving at the time, despite a court ruling that she was.

Mr Justice Stuart-Smith said the sentence was the shortest possible and drew attention to Onasanya’s ‘exemplary character’. He added: ‘You do not accept the correctness of the conviction; but I have to sentence on the basis that the disaster which has befallen you is self-inflicted.’

Between January and June last year, the number of inmates freed under home detention curfews, which allows them to be released with a tag, soared by 50 per cent from 2,196 to 3,304. The Ministry of Justice declined to comment last night.