A former independent reviewer of UK terror laws is among a trio of legal and political experts appointed to a body set up to assess paramilitary activity in Northern Ireland.

Evidence of Provisional IRA activity is of sufficient strength to force the exclusion of Sinn Fein from the North’s powersharing government, the Democratic Unionists have insisted.

Former justice minister Michael McDowell said he believed the IRA has “effectively been stood down as a paramilitary organisation” — but that hardline members continue to use “extreme violence”.