There’ll be some sighs of relief in Canberra and groans from within security agencies after Labor MP Anthony Byrne was prevailed on to reverse his decision to leave the parliamentary Joint Committee on Intelligence and Security.

Byrne was Labor’s deputy chair on the crucial committee and its most experienced member, but had decided to move on, having grown frustrated with unsuccessfully pushing for reform of the way Parliament oversees intelligence and security agencies and issues. Earlier this week, right-wing Victorian Liberal MP Michael Sukkar was revealed as the new chair of the committee, in the wake of Andrew Nikolic’s defeat in the election; Sukkar has only been in Parliament since 2013, has no security or intelligence background and little committee experience, making it more likely the committee would be given the runaround by agencies and bureaucrats.

Senior Labor figures had urged Byrne to stay with the committee, as had some intelligence academics, and it is understood elements of the Australian Intelligence Community, as the intelligence and security apparatus is collectively known, also wanted him to remain, despite Byrne’s often testy relationship with agencies. The Victorian MP has not been averse to publicly savaging bureaucrats, particularly from the Attorney-General’s Department, where an attitude that cooperation with parliamentary committees is optional has long been in place. With the inexperienced Sukkar as chair, Byrne’s presence is more necessary than ever.

The consequence is likely to be much greater pressure for further reform of the committee’s remit, especially given the weak position of the Turnbull government and the make-up of the Senate. Nick Xenophon has had a long interest in transparency and civil liberties issues and has pursued them in the national security space through other committee processes, while the Greens and libertarian David Leyonhjelm have fought rearguard Senate actions against increasing national security powers as well.

In the previous Parliament, Labor had introduced a private members’ bill overhauling the committee along lines proposed by John Faulkner and Byrne, which was opposed by the government. Among other changes, the bill would have reduced the restrictions on who could be on the committee and explicitly opened it up to “recognised parties” within the Parliament, potentially allowing a Greens senator like Scott Ludlam to join the committee. The government may now have a tougher fight stopping a similar bill bill with Reps crossbenchers Andrew Wilkie — who was a valuable member of the committee in the Gillard years — and NXT’s Rebekha Sharkie potentially in play if the government has trouble mustering a majority.