Immigration Minister Liam Byrne has been fined £100 after admitting using his mobile phone while driving.
Mr Byrne has been a Home Office minister since May 2006
The Birmingham Hodge Hill MP was also ordered to pay £35 costs and given three points on his licence at Sutton Coldfield Magistrates' Court.
Mr Byrne, who pleaded guilty by letter, said he had been taking an important call on a deportation matter but there was no excuse and he was remorseful.
The former police minister was stopped on 6 July on Birmingham's Tyburn Road.
The Home Office has declined to comment but Home Secretary Jacqui Smith, who was put on the spot earlier by reporters, said she was happy with the work he was doing.
Mr Byrne has campaigned vigorously on road safety since entering Parliament, tabling a petition in 2005 from constituents calling for tougher penalties for dangerous drivers.
He once told a parliamentary committee that the most dangerous drivers were "serial potential killers" and said he was "shocked" at the leniency of sentences handed down to them.
His website lists safer roads among the eight priorities on his Action Plan for Hodge Hill.
He sat on the parliamentary committee which shaped the 2006 Road Safety Act, which increased fixed penalty fines for driving while using a mobile.
Mr Byrne, 37, who is also minister for the West Midlands, admitted an offence under the Road Traffic Act 1988.
In his letter he said he was involved in an important telephone call about deportation but realised that he should have pulled over.
He apologised to the court for taking up their time. He was fined £100 and told it would have been £150, but for his prompt guilty plea and expression of remorse.
His licence was also endorsed with three penalty points - he already had three points on his licence - and ordered to pay £35 costs.
Driving while using a hand-held mobile phone was banned in 2003, through an amendment to the Road Traffic Act's Road Vehicles (Construction and Use) regulations.
It was toughened up further in February when the minimum fine was raised from £30 to £60 in addition to three penalty points.
Figures obtained by the BBC News website in September suggest thousands of drivers continue to flout the law. In the north east of England alone, 3,045 notices were issued by police between February and August.
Kevin Clinton, of the Royal Society for the Prevention of Accidents (RoSPA) said Mr Byrne should have known better.
"The Home Office is responsible for the law and its ministers should be well aware of it and set the correct example.
"Far too many lives have been lost needlessly because of mobile phone calls and whether you are on a hand-held or a hands-free phone you are four times more likely to crash.
"It is good to see him being treated in the same way as other motorists and it shows that people who flout this important law do get caught and punished."