Feelings were running high in London last month in a lengthy pay disputeGetty Images

British Airways faces the threat of new strike action after announcing plans to close its main defined-benefit pension scheme because of a multibillion-pound black hole.

It was revealed yesterday that the flag carrier wanted to shut the New Airways Pension Scheme (NAPS) after the fund’s deficit ballooned to £3.7 billion.

The airline insisted that it was Britain’s biggest pensions deficit relative to the company’s overall financial value. A number of FTSE 100 companies are tethered to enormous pension shortfalls, including an estimated £7.6 billion deficit at BT and a hole at Tesco worth more than £5 billion at the last measure.

Under the plans, staff will no longer be able to make new payments into the scheme, although benefits already earned by its 17,000 members…