One of the basic rules of a political party is that members do not incite voters to vote against the party's official candidates. It is a clear cut rule that is held by nearly all significant parties and one that has been enforced irrespective of the identity of the individuals involved.
The news that Conservative Party donor Stuart Wheeler has given £100,000 to the UK Independence Party (BBC News: Tory donor gives £100,000 to UKIP) is a clear cut breach of these rules. There can be no two ways about it - UKIP is a rival party. Wheeler cannot remain a member of the Conservatives whilst endorsing a rival.
Back in 1999 the party did not hesitate to expel members, even some once-medium sized names, who had endorsed the "Pro-Euro Conservative Party" when it stood against the Conservatives. The same principle must apply to Wheeler. There can be no double standards on the basis of which way a lot of people in the grassroots feel about the issue of EU membership.
Hattip to ConservativeHome Tory Diary: Eric Pickles must expel Stuart Wheeler.