LONDON, May 12 (UPI) -- More than 12,000 Rail Maritime and Transport Union members in Britain have been asked to vote on a possible strike, union officials said Monday.

Union officials called a recent Network Rail offer on work conditions for maintenance and signaling staff "unacceptable."

They also warned the first rail strike in Britain in 14 years would "paralyze" the country, The Daily Mail reported.

A strike could start as early as May 29, the report said.

Separately, 5,000 signal workers will be asked to vote on pay issues.

Union General-Secretary Bob Crow said the company "is looking to cut its maintenance budget by up to 12 percent year on year" and "they are already moving to sneak inferior conditions in through the back door."

The director of human resources for Network Rail said the pay offer, including a 4.8 percent raise this year and a raise amounting to 0.5 percent plus a percent equal to the rate of inflation next year was "fair and reasonable."