The opening of Weston-super-Mare's new £51 million pier could be delayed further – because one of the main sub-contractors working on it has gone into liquidation.

Bristol engineering firm Joyner Morgan, which was the main mechanical services contractor on the pier, went into voluntary liquidation on Friday.

It is believed around 40 staff have lost their jobs.

Staff working directly for Joyner Morgan – a range of plumbers, electricians and engineers, were phoned on Monday and informed

Joyner Morgan managing director, Geoff Jones, confirmed it had gone into voluntary liquidation, but refused to comment further.

The news will put further pressure on John Sisk and Son, which is already two months behind with the completion of the project.

The pier, which was destroyed in a fire in July 2008, was due to be handed over to its owners – Kerry and Michelle Michael – at the end of June.

But the handover never took place because work was not finished and an opening date for the landmark has still to be confirmed.

Contractors are still on site completing a number of jobs, including fitting decking around the pier and installing lighting and partition walls.

A number of firms sub contracting for Joyner Morgan have not been paid.

Bristol-based firm Leader Air Conditioning was installing air conditioning on the pier and although the work has been completed and signed off, the firm, which employs 12 engineers, is still owed money by Joyner Morgan.

Leader Air Conditioning, which has been trading for 24 years, had most of its engineers on site since April, many working around the clock to get the job finished on time.

Leader Air Conditioning managing director, Mike Ward, said: "We have completed our air conditioning work on time on the pier and have not been paid in full.

"We are currently owed around £50,000 by Joyner Morgan.

"There is no doubt this debt puts a strain on my company's finances, but we are determined to trade our way through this situation.

"There are also a lot of other companies and suppliers that are still owed money for their work on the pier."

Another company also owed money by Joyner Morgan is Feltham and Sons Ltd, based in Stoke Gifford, which carried out some of ventilation and ducting work at the pier.

A team of six engineers started work on the pier in May and completed their work a month ago.

Director, Martin Feltham, who has built the business up from scratch and works with his two sons, said: "Everyone has bust a gut to get the work on the pier finished.

"We have worked well with Joyner Morgan for the last 25 years and have always found them to be a great company.

"Joyner Morgan owe us £50,000 in total, a large proportion of which is for work carried out to the pier.

As with all major contracts, penalty clauses are included if a job is not finished in time and it is understood that Sisk is to pay the Michaels an agreed amount in compensation.

Bosses at Sisk met with the Michaels last week to discuss the project but a completion date for the pier has still yet to be agreed.

Mr Michael said he was not prepared to comment on the news that Joyner Morgan had gone into liquidation and any effect it may have on the pier rebuilding programme.

The pier is not expected to open until September at the earliest and the Michaels say the fact work is not finished and the landmark is closed, means they are losing £1 million in revenue a month through the peak summer season.

Bosses at John Sisk and Son, who have been working since April 2009 on the project to rebuild the landmark, confirmed all money due to Joyner Morgan has been paid.

A spokesman for John Sisk and Son said: "Having checked our records, we can confirm that all invoices to date have been paid by their due date.

"As a family run business, we go to great lengths to ensure that all of our subcontractors are paid what they are due on time and without delay.

"We continue to work together with our subcontractors to complete the works, returning this landmark of Weston-super-Mare back to its rightful iconic place at the heart of the community."