The estimate of how many FCA staff will take part in industrial action - if it goes ahead - is based on FCA internal forecasts.

The regulator expects the vast majority of staff to work as normal if a strike takes place.

The Unite trade union said that 75% of Unite members working at the FCA voted in favour of strike action  with nearly 90% of members prepared to work to rule.

The FCA employs approximately 4,000 staff with an estimated 600 in the Unite trade union, about 15% of total staff. The 75% of Unite members who voted in favour of strike action would equate to about 450 staff however it is not known how many of Unite’s 400 members took part in the strike ballot. Financial Planning Today has contacted Unite for clarification on the number.

While the FCA expects only a minority of staff to support the strike, if industrial action is called it is possible that most or all Unite members will support it and other trade union members may also back it.

Despite this it is understood the FCA is not expecting widespread disruption, even in the event of a strike. 

The Unite union is not officially recognised by the FCA for bargaining purposes but is seeking this status.

Unite has accused the FCA of planning to cut staff salaries by proposing an imminent pay and benefits shake up which will see nearly all staff bonuses axed, potentially cutting staff packages by 12%. It wants the arbitration service ACAS to get involved to settle the dispute.

The FCA has proposed a new package which is says will substantially raise salaries, particularly for the lower paid.

A spokesman for the FCA said: “Our new employment package is highly competitive, providing fair, competitive pay at all levels and rewards strong, consistent performance. Most colleagues are receiving an average 7% increase in base pay this year and over 12% over the next two years, with an additional one-off cash payment of 4% in May. 

“Our lowest paid and strongest performers will receive more. The changes we have made ensure the FCA’s pay and benefits package remains one of the best, if not the best, of any regulatory or enforcement agency in the UK. While we acknowledge the recent vote, we respect colleagues’ decision and understand the strength of feeling about some of the changes we have made.”  

A substantial staff consultation exercise was carried out before the FCA's new pay proposals were put forward in early March.