The Dáil's Ceann Comhairle could be facing a motion of no confidence - unless he withdraws comments about the opposition.

Sean Barrett told RTÉ Radio it was "perfectly obvious" that Fianna Fáil and Sinn Féin are 'out to undermine him, to get him' by questioning his decision to block a debate on a Commission of Inquiry.

It's been confirmed today that Mr Barrett received a letter from Alan Shatter, asking him to cancel a planned debate on issues relating to the Guerin report.

But he has denied that the letter in any way influenced his decision - saying he was bound by the rules of the Dáíl, irrespective of Shatter's contact.

However opposition parties have now raised new questions over his future - after taking issue with Barrett's claim that the dispute is politically motivated.

Sinn Féin - which has already said it does not have confidence in Barrett's position - has called on him to withdraw the remarks.

And Fianna Fáil leader Micheál Martin has said his party could also withdraw its confidence in him unless the contentious remarks are now withdrawn.

Our political correspondent Gavan Reilly filed this report for Today FM's National Lunchtime News: