Workers’ representatives have expressed anger over the decision to award MPs a pay rise above inflation and almost double that offered to parliamentary staff.

The 2.7% pay hike for MPs, taking their basic annual salary from £77,379 to £79,468, is well above the 1.5% received by those serving them in the Commons and the 1% offered to many civil servants.

The £2,089 increase to their income announced on Thursday by the Independent Parliamentary Standards Authority (Ipsa), effective from 1 April, far outstrips the current inflation rate of 1.8% on the main CPI measure.

MPs’ pay is linked to average rises in the public sector, as determined by the Office for National Statistics. Following reforms to the way MPs’ pay is calculated, the rise is automatic and not subject to a vote in the House of Commons.

But Mark Serwotka, the general secretary of the Public and Commercial Services union, said: “It is an outrage that MPs are rewarding themselves with an above-inflation pay rise while civil servants, who do some of the most vital jobs in society, are still subject to a cruel 1% de facto pay cap.

“PCS are balloting 120,000 members for strike action over pay this summer and today’s news will only anger them further.”

The deputy general secretary of the Prospect union, Garry Graham, said: “Our members will see more than a whiff of hypocrisy and double standards in today’s announcement.”

Graham said that Prospect’s calls for an independent review of pay in the civil service and wider public sector had been repeatedly turned down by ministers. “There has not been a government in peacetime so reliant on the hard work and dedication of the civil service and its agencies,” he said.

“For MPs to be awarded 2.7% when pay rises for those who serve them are held down at 1.5% or less demonstrates a remarkable level of contempt. As we prepare for pay discussions with the Cabinet Office and Treasury, this announcement will only add to the anger and frustration held by members.”

This year’s rise followed a 1.8% rise in MPs’ pay last year and 1.4% in 2017, both of which represented real-term pay cuts, and inflation-busting rises of 1.3% in 2016 and an increase from £67,000 to £74,000 in July 2015.

Mark Serwotka, general secretary of the Public and Commercial Services union, said the pay rise was ‘an outrage’. Photograph: Guy Bell/Rex/Shutterstock

The 2.7% figure was announced by the ONS on an interim basis in December and confirmed last week to Ipsa, which made the final announcement.

Chairs of Commons committees will enjoy a 2.7% increase to the additional salary they receive on top of their basic pay, taking it from £15,509 to £15,928.

A Downing Street spokeswoman said: “The decision taken today is independent of government and parliament. What government sets are ministerial salaries and they have been frozen since 2010.”

The Labour MP Kevin Barron said: “I am very disappointed to see that Ipsa has awarded MPs a 2.7% pay increase but only 1.5% for parliamentary staff. I urge them to look again at the budgets as it cannot be right that the gap is so great.”

Unison’s assistant general secretary, Christina McAnea, said: “Politicians should now turn their attention to making sure public service workers on outsourced contracts get above-inflation pay rises, too. Many of them missed out on NHS and council pay rises last year but do the same jobs as colleagues. People delivering essential public services shouldn’t be forced to survive on poverty wages.”

Max Freedman, who chairs the Unite union’s parliamentary staff branch, said workers were only receiving a 1.5% pay rise.

He added: “This real-terms cut for staff of MPs is inadequate and unacceptable, and the fact MPs will be seeing a significantly higher rise is insulting. It seems it’s one rule for elected MPs and another for their hard-working and hard-pressed staff. The huge extra pressure on parliament has significant ramifications for the workload of staff, and this decision will feel to many like a slap in the face.

“Ipsa has failed to properly consult with Unite reps despite our repeated calls for staff to get a fair deal. We have written to Ipsa raising our concerns, and will continue to fight for the real-terms pay rise staff members deserve.”