The move reflects the anger among staff represented by the union Prospect who feel that their goodwill in ensuring the organisation achieved all of its key performance indicators for 2006 is being rewarded with a real terms pay cut.

Members will receive ballot papers on Tuesday January 16 with a result due on February 2. A positive vote will begin a campaign of discontinuous strike action starting with a one-day walk-out.

Prospect negotiator John Higgins said: "HA’s managers are patting themselves on the back because all of their key performance indicators have been met. But this was only possible because members worked above and beyond their contracts to provide 24/7 cover on time and on budget."

This included completion of a project to provide traffic officers across England’s motorway network to keep the traffic moving following collisions or in areas of congestion.

"Their diligence in keeping the traffic flowing has earned them the nickname jambusters. But, after previous modest pay settlements, Treasury constraints have resulted in management imposing an offer that not only fails to provide ‘jam tomorrow’ but will see 80% of members taking a pay cut," said Higgins.

Civil service employers were instructed to construct pay offers for 2006 around an assumed inflation rate of 2%. But the union argues that the consumer price index stands at 2.7% while the retail price index, which includes the cost of housing and council tax, is 3.9%. Although the deal is worth 3.6% overall, funds allocated to correct a pay progression problem created by HA mean the majority of members would only receive 3% on basic pay.

Prospect represents over a third of all Highways Agency employees, including 70% of the 1,100 staff based in the seven regional control centres and outstations – South Mimms, Godstone, Avonmouth, Birmingham, Nottingham, Warrington and Wakefield – which have hands-on responsibility for the UK’s roads.

Other members include 370 engineers and specialist technicians based at HA’s London headquarters and seven regional offices in Leeds, Bedford, Manchester, Birmingham Bristol, Exeter and Dorking.