The London North West Healthcare Trust finished the last financial year with a deficit of £56m, says Labour research.
The Trust which covers Ealing, Northwick Park and Central Middlesex Hospitals was found to be £8m in excess of their predicted deficit.
The Trust has attributed the £8m deficit to pressures over the winter, but Labour says as NHS funding has failed to keep up with demand from a growing population, over 2,000 beds have been cut from the NHS across London over the last five years.
Labour's parliamentary candidate for Ealing Central & Acton, Rupa Huq, recently led a survey asking 535 local people about the NHS. Results showed 71% of respondents think the lack of GP access is putting a huge strain on A&Es and 75% of them agree that Labour's 48-hour maximum GP waiting time pledge should be a priority.
Ms Huq said: "I have noticed it takes a lot longer to get a doctor's appointment in recent years and the waiting time crisis at A&Es across the borough, caused by the Tories closing two of our A&E units, is very worrying. Even more so is the proposed closure of our remaining two A&Es and the only maternity unit in the area.
"I hope to be elected and work with a Labour government, so that we can rescue the NHS with 8,000 more GPs, 20,000 more nurses, 3,000 more midwives and a commitment to review our currently doomed A&Es."
Simon Crawford, director of finance at London North West Healthcare NHS Trust, said: “There is more work to do, but by joining up care across our hospitals and community services the merger has put the trust in a stronger position to provide specialist, 24/7 patient care across Ealing, Brent and Harrow.
“This winter the whole of the NHS experienced significant pressures, including an increase in those patients requiring one-on-one care. Ensuring that the trust was appropriately staffed and able to care for our patients during this very busy period was a major factor in the £8m overspend.”