The criticism follows a government announcement that it is awarding some public sector workers their biggest wage increase in almost 10 years.
“Without extra money from the Treasury to fund these pay increases, services and jobs somewhere will have to be cut,” said Unison assistant general secretary Christina McAnea.
“Sadly these pay rises won’t be pain free for schools and police forces. Without extra resources, already beleaguered budgets will now have to be raided.”
The pay rise will mean members of the armed forces will receive a 2.9% increase, teachers will get 3.5%, and prison officers will receive 2.75%.
The home office announced that police would also receive a pay increase of 2% in 2018–19, taking the average pay for a constable to more than £38,600 annually.
Home secretary Sajid Javid said: “This award represents the highest consolidated pay award since 2010.
“I’ll continue to fight on behalf of police to ensure they have the resources they need to do their jobs effectively.”
The government says that the pay increases will be funded via departmental budgets and not from the Treasury.
The announcement follows a pay rise for NHS staff of 6.5% over three years agreed in March. This deal was funded through a special allocation from central government, meaning no funds would be directed away from NHS services.
The GMB union criticised the government for announcing the pay rise on the last day of Parliament before summer recess.
Rehana Azam, GMB national secretary, said: “One million public sector workers have been left in limbo by this cloak and dagger briefing on the last day of Parliament.”
In June members of the largest civil service union in the country, PCS, voted to strike over pay, but because less than 50% of its members voted they cannot legally strike.
