A description of the various motions passed at the 2010 Liberal Assembly has been posted on the Liberal Party's website:

The Liberal Party ::

The motions include one reaffirming the party's support for decriminalization of the personal possession of drugs:

Assembly notes the existing party policy in relation to the misuse of drugs.

Assembly re-affirms its commitment to the de-criminalisation of illicit drugs to the extent of personal possession.

Assembly wishes to clarify the existing policy to the extent that we would wish to see the supply of illicit drugs remain a criminal offence as per current legislation and sentencing policies.

Assembly envisages that the legal supply of drugs will be targeted at helping those with an existing drug problem rather than the ready and open supply of drugs to the public. It is further envisaged that the supply of such drugs will be channelled through existing treatment bodies and medical agencies.
The last sentence is a bit daft because that is exactly what already happens. Ask any pharmacist!

What really worries me though is the textual evidence elsewhere in the list of motions of the damage which cannabis can do to concentration. See for instance the section on the Big Society:

The Liberal Party ::

“The Big Society”
Assembly resolves to use the Coalition Governmentrsquo;s “Big Society” policy to campaign for the established Liberal Policies of subsidiarity and grass

Assembly believes that only if the "Big Society" is to be more than political hype and a meaningless PR exercise it must be rooted in democratic principles will it have any public credibility.

Assembly therefore resolves to campaign for the devolution down to Parish and Neighbourhood Groups; all possible First and Second Tier Local Authority Services, along with their budgetary share, and for Councillors at all levels to take a leading role in such groups in accordance with their role as Elected Community Leaders.
"...established Liberal Policies of subsidiarity and grass"? Like wow, man!