The FDA union is looking to extend its reach further into the civil service by launching a new organisation for officials at SEO and HEO level.
The union currently represents around 18,000 senior officials in the top tiers of the service – those at Senior Civil Service (SCS) level, and those working in Grades 6 & 7.
But the new union – dubbed "Keystone" – will allow higher executive officers and senior executive officers to become full members of the FDA. The organisation says it is not aiming to "compete with other unions for members".
In a letter to existing FDA members, general secretary Dave Penman (pictured) said the expansion marked a "major development" for his union.
"As the civil and public services have changed, so too has the FDA," he said.
"Whilst the FDA originated in the senior grades of the civil service, it now has as many members below grade 7 level as it has in the SCS.
"The changing membership of FDA has been the subject of much debate within the union over the past few years. This reached a conclusion in May this year, when our annual conference agreed to introduce rule changes that will fully open membership to those in the HEO, SEO and related grades. Today we are launching a new section of the union for those grades, called Keystone."
However, the move could prove controversial with other civil service unions, as it will open up the possibility of FDA membership to officials currently represented by the Public and Commercial Services (PCS) union.
The FDA has said it is not the intention of Keystone to move into territory occupied by other organisations.
"In the civil service, a number of unions represent staff at the same grade and potential members face a choice of which union they feel is most appropriate," the Keystone website tells potential new recruits.
"The aim of Keystone is to build union density in the civil service rather than compete with other unions for members."
But Civil Service World understands that the PCS – the largest of the civil service unions with more than 200,000 public sector members – has already raised concerns with the FDA over the new organisation.
In May, PCS general secretary Mark Serwotka used an article in the Morning Star newspaper to warn of "division and competition" among unions representing civil servants.
"Our movement’s longstanding inter-union agreements over how to organise across the economy are essential because we need united collective organisation in workplaces to advance our members’ interests," he wrote.
On Friday, PCS raised the prospect of "coordinated strike action" over chancellor George Osborne's confirmation that civil service pay rises are to be capped at 1% until at least 2019.
"Our national executive believes that public sector pay policy requires a co-ordinated response from public sector trade unions, including industrial action," a statement from the union said. PCS has promised a "major consultation exercise" on public sector pay in the autumn