The union representing workers for the Santa Clara Valley Transportation Authority said its members planned to strike Monday morning, putting the daily commute plans of tens of thousands of people in flux.

The Amalgamated Transit Union Local 265 submitted a letter at Thursday's VTA board meeting notifying its intent to strike beginning Monday at 12:01 a.m. The union represents over 1,500 workers, including bus drivers, dispatchers, and light rail operators, and customer service reps who help transport about 100,000 passengers daily.

The current deal between VTA and the union will end after 11:59 p.m. on Monday. Raj Singh, president of ATU Local 265, told CBS News Bay Area on Monday that the two sides were at an impasse and that nearly 96% of members voted last month to authorize a strike.

VTA said late Thursday that bus and light rail service may not run starting Monday morning, and other routes that run past midnight may be interrupted. Paratransit service would continue to run regular operations.

"VTA is extremely disappointed that ATU is leaving the communities of Silicon Valley stranded without much-needed bus and light rail service, said VTA deputy general manager Greg Richardson in a prepared statement Thursday evening.

On Friday, the agency and union gave their "last and best" offers. According to the union, the agency is offering a 9% rise in pay over three years, with 4% in the first year. VTA said the increase, compounded over the 3-year period, is 9.3%.  

Singh says resolving conflicts in the workplace is a major sticking point, claiming that the agency has refused to go to arbitration more than a dozen times in the past year and a half. 

VTA is encouraging residents and businesses to prepare for alternative travel methods such as carpooling, ridesharing, regional rail, walking, and biking.