Taxpayers may have to wait months to find out whether the overrunning Ancient Market Place regeneration scheme has cost more than its £3m budget.
Traders finally moved back to the market from Memorial Gardens on Monday, a month later than originally planned, with contractors Balfour Beatty still working on site.
It is understood the building firm and Kingston Council reached an “acceleration” agreement to meet the extended deadline of May 16.
Builders worked overtime and at weekends to hurry up the project, at extra cost.
Conservative Councillor David Cunningham accused the ruling Liberal Democrat party of speeding up the project in order to finish before today's local elections.
He said: “I have my own reservations about the scheme, but I am mainly unhappy because they are spending extra money in order to pull back the completion date for political reasons.”
Council leader Liz Green said who pays for the project would be decided when the marketplace is finished but denied it had been rushed in time for election day.
She said: “As far as I’m aware, we are not over budget but we won’t know until months down the line.
“If the overrun was the contractor’s fault then they will pick up the tab, if it was our fault then we pick up the tab.”
Traders returned to the market place on Monday after 12 weeks in Memorial Gardens
Project manager Mark Teasdale said he was no longer willing to answer questions and referred calls back to Kingston Council.
Mr Teasdale’s phone number is advertised on the project website saying: “Mark is the Kingston ancient market project manager. Mark can explain how the scheme fits into the council’s wider vision for the enhancement of Kingston town centre.”
A Kingston Council spokesman declined to answer questions as to whether the project was expected to be over budget. Last week it was claimed the project had not overrun.
No explanation has been given as to why several different finish dates were still being displayed on the project website.
A statement said: “As stated last week, we are getting on with finishing the last few bits of work to complete the whole market place project during the rest of May.”
Kingston Council has invested £1m into the project, with the other £2m coming from the Mayor of London.
That money was provided with the agreement that the work would be finished by the end of the 2012-13 financial year, which was early April.
It is understood the council negotiated an extension when it became clear the project was not going to meet the deadline.
Initially, the council said the market stalls would be fully fitted by May 4, with traders opening for business on either May 10 or May 11.
The deadline was then pushed back again, to May 16 – when stallholders finally did move back on to the site.
* A popular, long-standing market trader was temporarily suspended from Kingston’s new market place just a day after moving into his new stall.
Gary Phillips, who runs GD Phillips salad stall, was booted off the new £3m market place on Tuesday morning after climbing on to the roof of his new stall to put up his shop sign.
He said after being spotted he was called down and suspended from the market for the rest of the day.
Mr Phillips, who often shouts “avocado!”, said: “We had to climb up on the roof to put up our sign and they saw me do it.”
He said he was told forcefully to get down and then he was suspended for the rest of the day.
He said: ”I lost a couple of people’s wages and a day’s trade.
“I thought it was diabolical, but what can you do? They hold all the cards.”
A spokseman for town centre managers Kingstonfirst said Mr Phillips was suspended for climbing on the stall roof.
Mr Phillips was back on the market on Wednesday.