I think the line: "All candidates are invited to put up a statement for consideration for inclusion on this web site" explains the situation.
My understanding is that the labour candidates are the only ones to submit a statement to MiA to include on their web site at present, but all other candidates are invited to do so.
This is rather than copying any statement that has been made elsewhere and publishing it without permission. Any candidates wishing to make a statement for this purpose, or wishing for an existing statement to be included on the MiA web site should get in touch with MiA Chairman David Hoyle using info@marple-in-action.org.uk