Sir Malcolm Rifkind has said that security chiefs speaking to MPs in public today was "an historic occasion" that will be repeated.
The Chair of the Intelligence and Security Committee added that he believed those involved were glad of the chance to speak publicly.
He said: "Many of them have been upset at the accusations that they have been doing something improper or doing something unreasonable to their fellow citizens.
"I suspect they were pleased to have the opportunity in public to speak about the work their own staff do and how important it is to the national interest."
More top news
Bright & breezy with some showers
ITV News witnesses the devastating aftermath as 600 people remain missing and 300 are confirmed dead.
Wayne Lotter, the co-founder and president of the conservation organisation PAMS Foundation, has been shot dead by gunmen in Tanzania.