Royal Mail has said there are "no grounds" for the strike action its employees voted in favour of yesterday, as tensions over a range of issues including pensions came to a head.

With a 73% turnout, the Communication Workers’ Union (CWU) members voted 89.1% in favour of taking action in the first strike ballot since Royal Mail entered the stock market as a private firm in 2013.

But the postal operator warned action would undermine the trust of customers and make it harder to pay for “industry-leading terms and conditions”.

In a statement, Royal Mail said: “There are no grounds for industrial action. There is a very good deal on the table. Royal Mail would continue to provide the best pay and terms and conditions in the industry.

“Royal Mail pays 45-50% more than the living wage and we are not proposing to change our core terms and conditions or our commitment to a predominantly permanent workforce.”

Royal Mail has made three pension offers so far, which have all been rejected by CWU, as well as by Unite. The price of its shares was down -2.66% this morning (4 October).

Under Royal Mail’s proposed new pension scheme, someone aged 50, earning £25,000 per year and retiring at 65, would retire on an annual pension of £12,300 and a tax-free lump sum of £81,800.

The CWU is asking to reduce the working week by one hour a year, from 39 hours to 35 hours by 2020, and for a pay increase of 1.5% a year.

Royal Mail’s latest pay offer includes a £375 lump-sum payment for 2017/2018, which would correspond to a pay increase of around 1.5%.

It added: “We remain committed to reaching a negotiated agreement with the CWU on pay and pensions.”

The CWU Postal Executive will meet later this week to determine the next steps and any future strike dates.