Hundreds of North Sea oil and gas workers could be sacked because they are too heavy to be helicoptered off their rigs in an emergency.

In two months a new rule means oil and gas workers stationed offshore in the North Sea cannot weigh more than 19st 7lb in full clothing and boots.

According to the industry’s health and safety boss there are 800 rig workers who face being sacked because they are over the weight limit.

Graham Skinner, the health, safety and security manager of Offshore Energies UK which represents the industry, warned: ‘On 1 November, if a worker turns up at the heliport over 124kg (19st 7lb), they will not be able to go to work.’

The rule is being introduced because the maximum winch load a Coastguard rescue helicopter can hold is 39st.

The load is calculated based on the average weight of a rescue worker which is 14st, plus a 4.5st stretcher, and the weight of the rigger plus their kit.

If the weight of the rig worker exceeds the limit the winch cannot be safely used by rescuers while in the sky.

The average weight of offshore workers has risen by over a stone since 2008.

Mr Skinner added: ‘We identified that there is a significant risk due to workers’ weight.

‘That affects all aspects of their offshore work from getting on the helicopter and travelling offshore, to working around confined space, working at height, but also in terms of how we might rescue them using the winch on helicopters.

‘When we looked at all of the risks, we felt it was important to make sure that we didn’t have workers who we wouldn’t be able to rescue if the worst thing happened to them.’

When the plans were announced last year there were 2,200 staff who were too heavy.

Now just two months before the rule is enforced 800 workers do not meet the requirements.

Mr Skinner told the BBC: ‘It is significantly less than when we started and that’s a great sign.

‘But we recognise there’s going to be some hard work to be done to continue to reduce that number in time.

‘I think the message here is for people who haven’t started yet, who think this isn’t going to happen or it’s going to go away, you really have to start now because with eight weeks to go it will still be possible.

‘It will be hard, but we’d like to have you as part of our workforce.’