Labour's vote buying on Newsnight
Newsnight's reporter did an excellent job in obtaining usable evidence that Labour candidates have continued buying votes. The advantage of buying postal votes is that it is easier to check that people have voted for the party's candidate. It is possible for people to show their ballots in the polling station.
They were paying about £15 a vote in 2004 and hence an increase to £20 per vote is only slightly in front of inflation.
What would be particularly interesting would be to trace how they get the money to pay for the votes. That investigation sadly is unlikely to happen.