A multi-million pound “same-day treatment centre” will open at the Whittington Hospital in a bid to stop A&E targets plummeting further after a third of beds are axed.

Data shows the NHS trust which runs the hospital in Magdala Avenue, Archway, has slipped from being in the top half of trusts across London, to the bottom half in a key national four-hour A&E target.

The figures show in 2010/11, Whittington dealt with 97.04 per cent of “type 1” A&E patients – the most severe category – within the timeframe.

This was in the top 10 of 22 trusts across London. However, figures for this year (2012/13) show the hospital has slipped to 15th place on the table.

Meanwhile, the percentage of “all-types” patients it deals with in the target has also declined, with five in every hundred patients not being dealt with appropriately within the four hour target, as opposed to three in every hundred three years ago.

The figures have sparked fears standards will deteriorate further and waiting times increase if plans to axe more than 100 of the hospital’s 360 beds while shredding 500 staff go ahead.

But the hospital claims the £2.9 million, 70-patient capacity centre due to open in November will prevent A&E targets from further decline.

Jeremy Corbyn, Labour MP for Islington North, criticised the same-day centre plans. He said: “The figures are very disappointing about treatment targets falling within A&E.

“Building this same-day treatment centre is not the solution to the issue. We need to ensure there are sufficient staff in A&E to deal with cases in the way it once did.

“This completely undermines the whole Whittington case for closing a very large number of beds and making 500 staff redundant.”

The same-day centre, currently under construction in the former X-ray department next to A&E, will act as an “alternative to admission”, provide face-to-face consultations, scans, X-rays and a range of other clinical procedures in 16 patient bays. It will be funded entirely by the trust.

Shirley Franklin, of the Defend the Whittington Hospital Coalition, said: “They are just pulling things out of a hat to seduce us.

“Why would they be spending money on this when they can do up the buildings they have and keep the buildings and facilities?

“Losing beds may mean people are waiting in A&E longer. A same-day centre with no beds is no substitute.”

A Whittington spokesperson said: “This facility will enable us to deliver same-day care as an alternative to admission.

“This will help the flow of patients through the emergency department and will further improve waiting times. Convenient follow-up care will be provided by our community teams in local health centres or at patients’ homes.”