Tony Blair is due to chair the first meeting of the ministerial committee on security and terrorism, which was set up as part of Home Office reforms.
Mr Blair will chair the committee, which will meet on a monthly basis
The committee, which is expected to meet monthly, will involve intelligence agency representatives, police and other relevant Whitehall bodies.
It is intended to streamline the approach to security threats.
Home Secretary John Reid and Foreign Secretary Margaret Beckett will be among those attending the meeting.
Shadow Home Secretary David Davis said the new approach was the wrong answer to the question of how best to tackle possible security threats to the UK.
He said: "The aim is right but a committee will not solve this problem.
"We need a single minister in the Cabinet, in the Home Office, working with the home secretary to concentrate on terrorism day in, day out. That is the only solution."
Meanwhile, the Liberal Democrats' home affairs spokesman, Nick Clegg, claimed that in reality Tony Blair is unlikely to have a hands-on role.
He said Mr Blair's chairing of the proceedings were likely to be little more than a matter of "formal protocol", with the home secretary chairing the meetings "in practice".
As part of new reforms, the Home Office will now concentrate on security and policing.
Meanwhile, prisons and the criminal justice system will become the responsibility of the Department for Constitutional Affairs, which will be renamed the Ministry of Justice.
The new ministerial committee will be backed by a new Office for Security and Counter-terrorism (OSC), which will meet weekly and be chaired by the Home Secretary.
Part of the OSC's role is to provide a forum for the intelligence agencies to pass on information to the police and other relevant bodies.