A struggling British offshore oil and natural gas sector held out its safety record as a critically important feature in the post-Brexit era.

"Safety critical maintenance has been -- and will remain -- a focus for industry," Mick Borwell, health, safety and environment policy director at industry group Oil and Gas U.K., said in a written statement Monday.

The group said earlier this year that exploration activity in the North Sea is at an all-time low and there are no signs of improvement. Less than $1.4 billion in spending on new projects is expected in 2016, compared with an average of around $7 billion in the last five years.

The group's chief executive, Deirdre Michie, said North Sea oil and gas fields are entering a phase of "super maturity," and while the opportunity for recovery exists, lower crude oil prices are adding insult to injury.

After the June referendum to leave the European Union, the industry body said there are very real difficulties ahead for the industry. Investment levels are a concern for the North Sea oil and gas sector as exploration and production activity dwindles in an era when the British economic future is uncertain and crude oil prices are low.

The price for Brent crude oil, the global benchmark based on North Sea oil, is down more than 11 percent since the June vote.

Oil & Gas. U.K. reported safety across the entire British continental shelf was improving with no fatalities, lower injuries and fewer releases than in past years.

"This is a testing time for the industry," Borwell said. "However, our report demonstrates that safe operations continue to be intrinsic to how we go about our activities on the U.K. Continental Shelf, regardless of the oil price."