Fears have been raised over how £43 million in cuts called for in a planned NHS merger will affect Harrow hospitals.
Ealing Hospital Trust and the North West London Hospital Trust, which already share senior managers and IT and estates departments, are expected to merge formally in April 2014.
A full business case is due to be submitted in July but Cllr Krishna James, the chair of Harrow Borough Council's health and social care scrutiny sub-committee, warned the effect of cuts in the borough is not yet known.
Cllr James said: “I’m very worried about what’s going to happen to the health services in Harrow, especially because there is already a strain on resources at Northwick Park Hospital.
“At the moment I still don’t know where the cuts are going to be made.”
In a report to councillors, Simon Crawford, senior responsible officer with the Ealing and North West London Organisational Futures Programme said savings targets of £30 million had been called for by the end of the 2012/2013 financial year.
A total of £16 million of this was to come from the North West London Hospital Trust (NWLH), with the trust on course to make £13.4 million in savings this year.
This includes £1 million cut from nursing and medical staffing costs, which the report says emphasised cutting bank and agency staff, vacancy rates and staff turnover.
Some £500,000 has been spent on reducing time patients stay and closing beds, and cuts of £8.6 million have been made on premises and procurement and £1.2 million in 'corporate functions'.
A further £43.3 million will be cut in the following financial year.
The report outlines that boards of both trusts are "committed" to the merger and further 'back office' functions may be shared.
It adds that 'on-call expertise' may be shared before the merger, although proposals that could affect patients would be discussed with councillors.
If the merger goes ahead, each trust will remain an individual statutory body responsible for meeting financial responsibilities and saving targets but will have joint programmes and share processes.
A spokesman for NWLH said a full business case outlining the details of the cuts would be published in July.
The health and social care scrutiny sub-committee will meet on Monday to discuss the plans.