Certainly, they are legally owned by their members, but if we look at who funds them, who pays for them, we can find out who's buying them.
The BBC looks at the electoral commissison's register of donations, here:
TheLabour Party received more than £5m in donations in the final quarter of 2004, new figures show. This is nearly half of the £11,724,929 received by 16 political parties listed by the Electoral Commission.That is a lot of money. And look. they're backing the winning horse.
Obviously, this includes Trades Unions, who must take their share of the blame for the Labour government, as well as Northumbria Water, who gave £4,999.00 to try and avoid their donation being disclosed, no doubt.
Check out the Labour Party's reigister entry here - you'll need to scroll down to the very end. Fascinating reading.