The company has grounded passenger flights as the coronavirus pandemic has prompted travel restrictions and slashed demand to fly.

On Sunday, Prime Minister Boris Johnson announced new rules will soon be imposed on people arriving in the UK from overseas, in a bid to prevent the spread of coronavirus.

Passengers will have to self-isolate for 14 days and provide an address when they arrive at the border.

But a source told Reuters these new measures could causes a delay, saying: ‘If the quarantine is in place, the earliest is August.

‘If there’s no quarantine, you could see, maybe, July.’

The quarantine policy would leave Virgin Atlantic unable to fill planes, the source added, meaning a resumption of flights would burn cash at a point when the airline is trying to preserve it.

The airline said last week it would lay-off almost a third of its workforce as it battles to stay afloat in the coronavirus pandemic which has brought air travel to a near standstill.

It is seeking hundreds of millions of pounds in support from shareholders through working capital facilities and deferments or alleviation of payments that are due.

It is also in discussion with creditors and the British government.

Virgin Atlantic is trying for a private-only deal to secure the future of the airline, the source said, with around a dozen private institutions expressing serious interest in a deal.

The government has not made it clear when quarantine measures will be put in place.