The developers, Quintain Estates and Lend Lease, plan to build 10,000 new homes, 3.69 million sf of offices, 645,000 sf of retail and leisure and a 26,000-seat sports and entertainment arena on the 190-acre site.

Now Livingstone has written to Greenwich saying he is "minded to direct refusal" of the plans unless the affordable housing quota is raised from its current 35% to 50%. He argues the smaller allocation will not meet the local needs as assessed in the council's housing needs assessment, nor will it address the strategic regional housing needs.

But the developers have the support of the council, London Development Agency and their social housing allocation is in line with existing government policy. Even so, the stance taken by the mayor is seen as important test of the extent to which he is and should be free to determine housing policy in the capital.

The mayor's draft housing policy is intended to address the problem of a chronic shortage of affordable homes especially for key workers like nurses and teachers. Huge price hikes in recent years have pushed housing out of the reach of many Londoners and the concern in the mayor's office is that this could ultimately stifle long term growth of the capital.

The development industry, though, argues that insisting on a 50% allocation of social housing in any new residential project could make many of these schemes financially unviable particular when economic growth is sluggish.