Norwich has missed out on up to £33m worth of affordable homes because developers are being excused from building the number they should, it has been claimed.

And the Green Party will this week call for City Hall to take a more rigorous approach to forcing developers to make 33pc of the housing which they build available as affordable homes.

That is the percentage set out in the joint core strategy - a blueprint for development in and around the city.

But the Greens say their analysis of 15 major housing developments approved in the city between 2013 and 2016 show that has not happened.

They say of the 299 affordable homes - which are aimed at people whose household income is below a certain level - should have been supplied if that requirement was met, just 39 were built.

At a meeting of the full council tomorrow night, Green city councillor Tim Jones will put forward a motion on the issue.

He will call for the council to uphold the existing policy that at least 33pc of homes in developments of 10 homes or more should be affordable.

The council's planning committee recently rejected planning permission for homes at St Peter's Church in Park Lane.

That was turned down because the developers were not willing to provide 33pc of affordable homes.

The developers had argued that would render the scheme unviable.

The council said the developer could offer £507,000 instead, to build the homes elsewhere, but the developer said no.

And Mr Jones will say the council should use that as 'the precursor to a new, more rigorous approach to holding developers responsible'.

The council's cabinet will also be asked to make viability assessments for developments available online to allow more public scrutiny and to automatically require independent assessments of those assessments.

A spokeswoman for Norwich City Council said: 'The council is committed to the provision of affordable housing and aims to strike the right balance between policy compliance and development viability, in order to achieve the best outcomes for the city.

'This complex issue will be discussed in detail at full council on Tuesday evening.'