Several thousand unionized office cleaners gathered at the Sheraton in Midtown Manhattan on Thursday. They voted to authorize a strike when their contract expires in December.

Local 32BJ of the Service Employees International Union say that their jobs are being jeopardized for higher wage earners and that building owners are seeking to eliminate pensions and reduce benefits, said NY1. The union vehemently opposes a wage structure that would pay new workers less than existing ones.

Everybody here wants to make sure that they have decent health care, decent pension and decent wages. The employers are saying we make too much and they wanna take it away, and we're ready to fight to keep it, said Mike Fishman, president of 32BJ, according to NY1.

The Realty Advisory Board, which represents building around the city, claims that union members in New York are the highest paid in the United States. They also said the last contract went into effect before the economic slowdown.

The asking rents in New York were about $90 a foot. Now the effective asking rates in New York are about $47 a foot. In 2008, vacancies were about 5.5 percent. Now vacancies are about 9.7 percent. So we have a huge loss on the revenue side, said Howard Rothschild, president of the Realty Advisory Board, according to NY1.

The strike is not set in stone, however, it could potentially kick off Jan. 1, since the current contract expires Dec. 31. The city's last office worker's strike was in 1996.