Opening Prime Minister's Questions on Wednesday, Theresa May said: "I'm sure the whole house will wish to join me in offering condolences to the friends, family and colleagues of police officer James Dixon from Thames Valley Police who was killed while on motorcycle duty yesterday and also to the family and friends of the passenger of the vehicle involved in the collision".
Tributes have been paid to an on-duty police officer who died along with a 91-year-old woman following a crash on the A4 in Berkshire.
Sky TV's Road Wars followed the work of Thames Valley Police officers.
RIP Dixie, it was a pleasure knowing you.
"In policing we often talk about the strength and importance of the police family and that is never more so as we share in the pain of loss and offer support to one another at this time of need".
The bike was being ridden by on-duty police officer Dixon, who was based at Loddon Valley police station.
Plot to kill British premier May foiled
Britain has suffered five terrorist attacks this year, in London and Manchester, in which a total of 36 people have been killed. Two Muslim men are suspected of conspiring to attack Downing Street armed with an improvised bomb, suicide vest and knives.
The driver of the auto was taken to hospital for medical attention. her injuries are not believed to be life-threatening.
Thames Valley Police said the next-of-kin of both PC Dixon and the dead woman had been informed.
Police constable Dixon was riding his police motorbike when the impact happened and officers were last night still at the scene.
She said: "I'm sure the whole house will wish to join me in offering condolences to the family, friends and colleagues of police constable James Dixon from Thames Valley Police who was killed while on motorcycle duty yesterday".
PC Dixon married his wife Samantha in February past year. "Our thoughts and Prayers are with his wife, family, friends and colleagues at this desperately sad time".
An IPCC investigation to determine the circumstances which led to the collision is underway, confirmed IPCC associate commissioner Guido Liguori.