The three-month prison sentence given to disgraced MP Fiona Onasanya is not unduly lenient, the Attorney General’s Office has concluded.

The Peterborough MP was convicted at the Old Bailey of perverting the course of justice after lying to police to avoid a speeding charge.

She was jailed in January, but is continuing in her role despite calls for her to stand down.

A complaint was made to the Attorney General’s Office that the sentence given to the 35-year-old solicitor was unduly lenient, but a review found it was not.

A spokesperson 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.”

If the sentence had been deemed to be unduly lenient, the Court of Appeal would have decided whether or not to increase it.

Parliamentary rules require the removal of an MP who is jailed for 12 months or more.

A lesser sentence can result in a recall petition, which can force a by-election if it is signed by more than 10% of the electorate in the constituency.

Onasanya, an Independent after being expelled by the Labour Party, is appealing against her conviction.

Jurors at the Old Bailey heard that Onasanya colluded with her brother Festus 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 that she was sent a Notice of Intended Prosecution (NIP) to fill out, but it was sent back naming the guilty driver as Aleks Antipow, an acquaintance of her brother, who was away visiting his parents in Russia.

Her brother received 10 months in prison after he pleaded guilty to three counts of perverting the course of justice over speeding, including over the July 24 incident.