Mr Lunn said the PAC had never had to deal with such a contentious issue as the RHI scandal.
“As a member of the PAC, I value the contribution it makes to our democratic process. It holds Government to account and works with the Northern Ireland Audit Office to make recommendations to ensure past mistakes are not repeated.
“The committee is cross-party and normally works in a cooperative way, with little display of party politics. However, it has never had to deal with an issue as contentious or politically divisive as RHI, and I doubt if we can achieve a cross-party consensus sufficient to produce a meaningful, agreed report.
“For that reason I support the demands for a judicial inquiry into the matter. The PAC has done some very useful work since starting its own inquiry, which may be able to feed into a legal investigation.
“The committee may continue its work on RHI or suspend it, but whichever way, the most likely route to the truth of what happened lies with an independent, judge-led inquiry.”