Contractors of all sizes with a strong track record in affordable housing are being invited to bid for two tiers of work packages worth up to £1m and upwards of £1m.

The housing associations are looking for firms that have used modern methods of construction and renewable energy technologies.

They envisage as many as 50 firms on the framework.

Invitations are being handled by the offices of Nottingham Community Housing Assoociation.

The other housing associations cover an area from South Yorkshire to Buckinghamshire and Warwickshire to Norfolk.

Firms have until 16 July to express an interest.