Members will start their action with a walk out at 12:30 on Friday February 8 and a half-day strike followed by a work-to-rule.

Over the week leading up to the day of action, members and staff will sign pledge cards committing them to a work-to-rule. As they walk out, their pledge cards will be collected and handed to the IPO. The work-to-rule will continue throughout February.

Prospect negotiator Helen Stevens said: “Members at the IPO have been treated worse than other public sector workers. Austerity for them has meant not only a pay freeze, but a freeze to their contractual progression to the rate for the job has also been imposed.

“This has cost them large sums of money and left a pay system that is fundamentally unfair and frankly shambolic. Our members at the IPO are highly skilled and work hard to support British business. Any hope of economic recovery depends on people like them. If they were in the private sector they would be in receipt of bonuses.”

Eleanor Wade, Prospect branch president, said: “The government's policies on pay have left the IPO with an unfair and discriminatory pay system and with equal pay cases outstanding. Central government pay restrictions are stopping the IPO from using its own resources to make a fair pay offer to staff, putting vital support for innovation at risk. Prospect members at the IPO are committed to fighting for fair pay.”

IPO is a successful government Trading Fund that regularly delivers large surpluses. A surplus of £8.5m was reported in 2010-2011 and one of £10.8m in 2011/2012. However, it is not allowed to use its profits to pay staff.

Stevens said denying progression also raises issues of fairness, equal pay and retention of staff. “Many patent examiners are working extra hours because of problems recruiting to these posts. This level of personal sacrifice is too much. The result of this ballot shows members determination to protest at such unfairness.”