Ocean Parcs, owner of the Pontin’s holiday camp chain, said it will close its Blackpool park due to poor trading and an unwillingness to invest the funds needed to revamp the ailing resort.

Ian Smith, chief executive, said the decision had been taken “with great regret”, and would result in the loss of 70 jobs at the 40-year-old park. He said: “We looked at it long and hard but bookings have deteriorated and the level of investment required for a short lease meant it was not commercially viable to continue.”

The Blackpool site will revert to Trevor Hemmings, the former owner of the Pontin’s group who retained the freehold when he sold the company to Ocean Parcs. Mr Hemmings, who has a 5 per cent stake in the group, is expected to redevelop the site.

Pontins also announced plans to invest more than £150 million upgrading the business over the next five years, up from a £50 million programme it announced in Febrary.

Most of the extra investment will be at its Southport holiday park, which will be completely redeveloped and renamed the Ocean Parc, Ainsdale on Sea.

The investment programme will add 2,800 jobs, including another 100 Blue Coats.

The company will also give customers and investors the chance to buy the new accommodation, either on a buy-to-let basis while customers or on a shared ownership or timeshare basis.

The Ocean Parcs boss said that, despite talk of a “staycation summer”, trading had been “a bit mixed”.

“We had a strong start but as the weather deteriorated bookings tailed off a bit. We’ll still do well, with turnover up 12-14 per cent, but not quite as well as we’d hoped at the start of the summer,” he told The Times.

He added: “Everyone anticipated the world and his wife were going to holiday at home. Well, the world and his wife still went overseas and had a few weekends away here.”