Boris Johnson has been accused of prioritising the super-rich in a controversial flat development, ahead of a 'day of action' over house prices tomorrow.

Green party leader Natalie Bennet said the London mayor was set to allow only 12% of a development of 700 private flats in Islington to be affordable housing, despite rules mandating a 20% minimum.

"Boris Johnson is once again riding roughshod over the people of London by privileging the profit of a developer over the need to provide ordinary Londoners with affordable homes," she said.

"By providing only 12% affordable housing in the new development, he's failing to allow for the development of a balanced community.

"He's not providing homes for the teachers, police officers, cleaners, and many other people who serve our communities, but setting up big profits for property speculators and private landlord."

Research from the mayor's office showed that two-thirds of all newly-built properties in London are being sold to investors, thereby pushing up prices even further.

Demonstrators will gather at Mount Pleasant in Islington from 10:00 GMT tomorrow.