"To support a referendum" means agreeing with the idea of holding a vote where the public can express their opinion on an important issue or decision. Full definition
Labour supported a referendum on AV at the election and is now opposed on the basis that the proposal is part of a wider package that includes changes to constituency boundaries. (independent.co.uk)
These options would all make a huge difference to the outcome and the level of support another referendum could receive. (politics.co.uk)
The democratic deficit - an evenly - split country, a growing mood for a second chance to decide, and neither main political party supporting a referendum. (politicshome.com)