The European Commission is going to the EU's highest court to push through an inflation-busting pay rise for EU staff opposed by European governments.
The Commission is pressing for a 3.7% pay rise for nearly 45,000 EU staff, including commissioners. It says the rise has been fixed in the EU budget.
But the 27 member states want to limit the pay rise to 1.85% because of tough economic conditions in Europe.
The European Court of Justice has been asked to issue a speedy ruling.
EC spokeswoman Pia Ahrenkilde Hansen said on Wednesday that the 27-member Commission had unanimously "confirmed its decision to take action before the court".
The Commission - the EU's executive arm - drafts laws and acts as guardian of the treaties.
Last month hundreds of staff at EU institutions took part in warning strikes in Brussels to press for the 3.7% rise.
The dispute threatens to disrupt European Parliament hearings starting next week, when the new commissioners-designate will be quizzed by MEPs.
At least 12 EU members, including the UK and Germany, argue that the pay settlement is inappropriate in the current economic climate.
The European Council - the body representing all EU governments - agreed on the 1.85% figure on 23 December.
Now the Commission wants to get that decision annulled, arguing that it violates rules for setting EU pay that were agreed with the Council in 2004, a senior Commission official told the BBC.
Basic gross monthly salaries for Commission staff currently range from 2,550 euros (£2,286; $3,720) for a secretary to 17,700 euros (£15,870; $25,823) for a head of department, the news website TheParliament.com reports.
The pay settlement for 2010 was based on 2008 figures, reflecting economic conditions that were much better at the time.
A complicated formula is used, based on civil service pay in eight of the EU's richer countries and on the cost of living in Brussels.
The Commission argues that the formula used is legally binding and that it is incumbent on national governments to foot the bill.
Some EU governments have already cut domestic civil service pay awards, in a drive to slash ballooning budget deficits.