Councillor arrested over tweet - Why not MPs as well?

The Daily Telegraph reports today (page 18) that a Tory Councillor has been arrested over claims that he had suggested on Twitter that a female journalist, Yasmin Alibaha-Brown should be stoned to death.
He has also been suspended from the Tory Party.

Surely the two Labour MPs who are alleged to have urged and congratulated the "student" demonstrators should suffer a similar fate? Along with the "University" staff who took similar public positions.
All should be suspended with immediate effect - they are all public employees and the public has every right to expect better of people in these positions.

Or is alleged racism a more serious matter than advocating and/or approving of criminal damage and attempted murder?