Workers at Thames Water in the GMB union may be balloted for strike action over job cuts and a threat to outsource call centre work to India.
The company, which is owned by the Australian banking group Macquarie, wants to slash 300 jobs.
It claims the recession means that people are not paying their water bills, prompting the cuts.
The GMB has 1,000 members at Thames Water working in three regions, including members at the firm’s call centre in Swindon.
Management are trying to force through “family unfriendly” changes to the call centre working hours and shift times, according to the union.