Treasury minister Lyndon Trott said the Public Services Department, which runs the airport, had known for some time that the work was required and had budgeted about £10m. for it.
‘Just before Christmas, T&R was made aware that the likely expenditure was anticipated to be considerably more than Public Services had originally indicated,’ he said.

Deputy Trott, who attended the presentation with chief officer Dale Holmes, said capital projects on the airport and harbours were usually funded from the Ports Holding Account. That was why no provision had been made for the work in the 2008 general revenue budget.
He said all funding options would be considered and he would not commit himself on whether the States would have to borrow the money.
‘No decisions have been made on the funding arrangements,’ he said.
‘The priority for Public Services is to determine exactly the extent of the essential works required and to report to the States.
‘The States will then be in a position to make the necessary decisions on a fully informed basis.’
Public Services minister Bill Bell was unable to say yesterday when the matter was likely to go before the House.
‘It’s a difficult question to answer precisely,’ he said.
‘The presentation on Friday was of the draft report, the consultants are still working on it and we will have to wait for the final version.’

The problem came to the fore early last week when airline Flybe said it had been told that it could not operate its new Embraer 195 jet into Guernsey fully laden because of deterioration to the runway.
General manager market development Ian Taylor said Flybe intended to meet Public Services and Commerce and Employment as soon as possible to resolve the issue.
Deputy Bell said that when his department had tried to set up a meeting with Flybe, the airline had declined because it had a board meeting on the day recommended.
The airline had wanted to use the Embraer as a replacement for the BAe 146 jet, which will be withdrawn from service in March.
Mr Taylor said yesterday that his airline’s eight locally based pilots had been due to start a three-month course on flying the Embraer.