Conservative leader David Cameron has named frontbencher Dominic Grieve as his party's new shadow home secretary.
Mr Grieve, 52, steps into the shoes of David Davis, who has resigned his Haltemprice and Howden seat in order to challenge the government over the 42-day pre-charge detention limit.
He had served as shadow attorney-general since being appointed to the job by former Tory leader Michael Howard in November 2003.
Mr Cameron described his new shadow home secretary as being "very well-qualified for the post" and a "star performer in parliament".
The Tory leader said: "My responsibility as leader of the party is to make sure at all times we have the strongest and most permanent team to take on this government and to offer the country an alternative.
"The work of the shadow home secretary cannot stand still. There is an epidemic of knife and gun crime in our country. We need to do more to get the police on our streets. There are problems with drugs and, yes, with terrorism. So that is my responsibility, to have that strong team."
Neither the shadow Cabinet nor the Conservative party approved Mr Davis' decision to resign and Mr Cameron made clear that it was Mr Davis' by-election to fight - not the party's.
"I wish David Davis well in his by-election campaign," Mr Cameron continued.
"I know that Conservatives including me will want to go and support him but my responsibility is that permanent strong team ready for government."