The head of NHS London has warned the government risks “stifling the ambition” of clinical commissioning groups if it does not find a way to speed up service reconfigurations.

Dame Ruth Carnall told the London Health 2012 conference that protracted approval, consultation and overview and scrutiny panel processes could stop CCGs making radical changes.

The strategic health authority’s chief executive also outlined the dramatic reconfigurations which need to take place in the capital.

She said that, while she was proud of the work NHS London had done on stroke and trauma, it should have begun work on cancer pathways and improving hospital productivity earlier.

She said: “It turns out to be a wholly unsustainable provider landscape [in London], we can’t continue to deliver 24/7 [services] at every provider across London.”

Proposals are currently being considered, and are at different stages, to downgrade accident and emergency units at Central Middlesex, Ealing, Charing Cross, King George and Lewisham hospitals.

Dame Ruth’s comments about the scale and speed of change needed  come a month after the report of a special administrator appointed to South London Healthcare Trust recommended breaking the trust into its component parts, following his appointment under the failure regime.

The failure regime process is considerably faster than a normal reconfiguration and the administrator’s final recommendations will go to the health secretary for a decision in January, without having to be approved by the Independent Reconfiguration Panel.

HSJ has learned NHS London is considering the possibility of merging Princess Royal University Hospital, part of South London Healthcare Trust, with King’s College Hospital Foundation Trust by April. It would be an accelerated process compared to previous mergers and might in future be applied to other providers.

Dame Ruth told the conference that care quality at South London Healthcare had been good, contrary to the main justification for putting it into the failure regime given by government.

She said the trust’s “clinical performance was good [but] financial performance was a disaster”.

In the letter to South London’s chairman in June, announcing the decision to apply the failure regime, Mr Lansley said: “First, and despite acknowledged recent improvements, patients are continuing not to receive the overall quality of care from the trust that is expected.

“While there have been some improvements in mortality rates, infection and maternity, concerns remain over the sustainability of these changes.”

The rest of Mr Lansley’s rationale was based on the trust’s financial and strategic position.