The NHS Confederation is to close its Birmingham offices - three years after chief executive Stephen Thornton reassured staff there were no plans for a move to London.

The announcement, at a meeting of the confederation's trustees earlier this month, means all 18 Birmingham staff members have been served with redundancy notices. In defence of reassurances offered in the past about the security of jobs in Birmingham, Mr Thornton told HSJ: 'That was three years ago.'

'People back then made the assumption that because I was appointed to the job and would be working from the London office that somehow it meant the whole organisation would have to move there.'

Mr Thornton said that had not been the case, but that the confederation's role 'had moved on considerably since then'. He said the development of offices in Scotland, Wales and Northern Ireland meant it was necessary to 'rationalise' in England.

He said the fact that the lease of the Birmingham office would run out on 31 January made it a ripe time to 'review the situation'. The London office would also be looking for new headquarters.

The staff - who make up almost half of the confederation's total workforce of 40 - will be able to apply for a handful of jobs in finance, events and marketing at the London office.

The confederation reckons the cost of the redundancies and the move will come to£150,000.

Mr Thornton said Birmingham staff had been told of the plans one day after the trustees' decision, and been offered human resources support. He said the move 'had not come as too much of a surprise' to staff, who had been involved in discussions before the plans were agreed.

There are also rumours that the confederation is facing ministerial pressure to merge with the Institute of Healthcare Management. But Stuart Marples, chief executive of the IHM, said he was 'not aware' of such rumours and insisted his organisation would resist any pressure for merger.

He said a debate at the IHM annual general meeting in October had welcomed further collaboration with the confederation, but had a mandate from members who were 'not prepared to see the two organisations coming together'.

The confederation was not available for comment.