This has clearly attracted a couple of Coleman-haters. But JackP is absolutely right, anyone involved in politics should know that perception, as much as reality, is as important. By not revealing his expenses he is inviting people to assume that there is something there.
And I would defend political parties in local government. Even where there are ‘independent’ councils groups tend to form with people who have shared views and visions for their area – in effect local political parties (which may or may not have parallels with the national parties). You need only look at the register of political parties to see how many ‘official’ local parties there are.
Some sort of organisation is needed to develop, articulate and deliver a vision for an area. If everyone voted independently on every issue, without some guiding vision, councils would be directionless and elections meaningless.