Harriet Harman, Labour’s deputy leader, is being prosecuted over her involvement in a car crash in which she was allegedly using a mobile phone.
The law which banned driving with a mobile phone was introduced by Labour in 2003, when Miss Harman was Solicitor General, one of the Government's top law officers.
Witnesses claimed that although Labour's deputy leader stopped briefly after hitting the parked vehicle, she drove off without leaving details of her insurance company or her car's registration.
But she will only be prosecuted for the driving offences, rather than leaving the scene, which could have left her with a possible six-month jail term.
Gordon Brown has signalled his support. The spokesman said: "He is fully supportive of her. She refutes the allegations and will deny the charges. She hasn't been convicted of anything. The Prime Minister has full confidence in her."
(Perhaps her confidence stems from the fact that the police do not appear to have seized her mobile phone after the crash and the evidence will rely on an eye-witness statement.)
Ms Harman has several previous driving convictions.
She was banned from driving for seven days and fined £400 after admitting speeding at 99mph on the M4 near Swindon, Wiltshire, in January 2003. She was said to be taking her son back to Bristol University after the Christmas break.
She was also fined £60 and given three penalty points for exceeding a temporary speed limit in Suffolk in April 2007