I am supporting John McDonnell for the Labour leadership. Not because I think there is the slightest chance of John winning if he were to get sufficient nominations, but because the Labour membership in the country needs to hear the arguments from across the range of opinions in the party.
John will raise issues which are important to Labour Party members that the other candidates will be anxious to avoid. The privatisation of public services, the wasteful PFI initiatives, anti-trade-union legislation, and the continued wooing of big business by the party are all concerns that need to be raised.
If John doesn't raise them, no one will, and the other contenders will not have to answer the questions.
We saw in the deputy leader contest the way in which Harriet Harman was forced towards Jon Cruddas's positions on issues such as Iraq when she realised they resonated with party members. A campaign that includes John McDonnell can do the same for the leadership issue.
Gordon Brown could never claim full legitimacy for his leadership because he had never had to have his position endorsed by members of the Labour Party. If the views put forward by McDonnell are squeezed out of a contest because Labour MPs do not want the party to hear them, whoever wins the leadership this autumn will suffer from the same weakness.
Labour MPs should give John McDonnell a voice in this contest. They have nothing to be afraid of but their fear.
Bob Piper is a Labour councillor for Sandwell. This is the first in a series of guest blogs on the Labour leadership.