I think we should, and the Charity Commission should not be an issue here. Much more vigorous lobbying & campaigning on specific issues are perfectly ok for charities, so long as they are in pursuance of their charitable objects, which must themselves not be just political. The CC guidance on political matters here http://www.charitycommission.gov.uk/publications/cc9.aspx#2 is pretty clear, & this is an area Jon Davies has experience of. In this case it is clearly in line with all versions of WMUK's Objects.

John