Who pays the piper?

Local Liberal Democrats have questioned the cost of "Local Voice", a tabloid newspaper distributed throughout the county borough on behalf of Labour in the Neath Port Talbot local election campaign. We have independently costed such an eight-page tabloid which makes extensive use of colour photographs. We chose a supplier who would be at least competitive with Trinity Mirror in Birmingham who printed the Labour election material, and came up with a figure of £5,400. (Anything less than this would suggest a subsidy by Trinity Mirror, which would have to be declared on election expenses.)

The question is: did every ward party chip in the £100 or so to pay for the newspaper (this would be on top of the cost of glossy colour leaflets they have already sent out)? Or did one or more of the big public service unions donate the upfront cost?