Councils in England and Wales are reportedly 'sitting on' £3bn allocated for new community infrastructure.
Research across more than 170 councils found that local authorities had an average of £8m in unspent funds from section 106 agreements, The Times has reported.
The total includes around £567m earmarked in agreements for affordable housing.
Councils also have £420m unspent in education contributions and £384m in highway contributions.
A further £334m of unspent funding has been designated for social infrastructure.
A Local Government Association (LGA) spokesperson said that although councils want to see developer contributions spent on delivery infrastructure and services, the process takes times and can be complex.
The spokesperson said: ‘There is sometimes a delay between the receipt of contributions and delivery of schemes that they will fund, which could include securing land and the need for relevant approvals.
‘In some cases, infrastructure project requirements set out in obligations can change and the project is no longer required, which might then require a new agreement to be made with the developer.
‘Infrastructure funding statements, which are now a legal requirement, provide an opportunity for councils to illustrate how they are using developer contributions to support infrastructure delivery in local areas.’