At most conferences there is at least one debate which proves how different we are from the other main parties. Different because we entrust Conference to decide party policy, in open debate, even where that may be at odds with the views of our parliamentarians.

Today’s debate on the ‘Secret Courts’ motion was a good example. The full title was F41: No Government Above the Law – The Justice and Security Bill.

This motion, submitted by two local parties, called on the Coalition to withdraw Part II of the Justice and Security Bill, which would empower Ministers to allow civil hearings and trials to be held in secret where national security is at risk of being damaged. Under this Bill neither the public nor, most significantly, the other party in a case, would have the right to see the relevant evidence, so would not be able to challenge it.

The motion also called on all our parliamentarians to press for the withdrawal or defeat of Part II of the Bill.

An amendment had been submitted which did not call for withdrawal of the Bill. Instead it said that closed material proceedings (ie secret courts) should be allowed as a last resort.

Several senior and well respected MPs and peers spoke in support of this amendment, including Jonathan Marks QC, Jim Wallace, Tom Brake MP and our Chief Whip Alistair Carmichael MP.

They argued that the Bill should be amended not abandoned, because some rare cases justified it. There was some discussion about the Public Interest Immunity system, where decisions about sensitive materials are taken by a judge. Those in favour of the amendment claimed that this system was not effective.

Even Julian Huppert MP, who is not known for meekly toeing the party line, spoke in favour of the amendment.

Ranged against them were Sarah Ludford MEP, Paul Strasburger from the Lords and several party activists, many of whom claimed that this was an issue that tested our commitment to civil liberties.

Robin Meltzer said that these principles are fundamental to who we are as Liberal Democrats.

Sarah Ludford memorably declaimed:

Nick Clegg said we should distinguish those policies we would die in the ditch for from those we could compromise on. Please jump into the ditch on this one, Nick.

Conference was not convinced by the supporters of the amendment and it was defeated substantially, quickly followed by overwhelming support for the main motion.

* Mary Reid is a contributing editor on Lib Dem Voice. She was a councillor in Kingston upon Thames, where she is still very active with the local party, and is the Hon President of Kingston Lib Dems.