A freedom of information request by local Liberal Democrats has revealed that Merton Council has thrown away £200,000 in developer compensation for the impact of construction and development.
There's also nearly £6m in unspent funds sitting on Merton Council's books that should be spent on improvement projects.
As part of the planning permission process, developers agree with Councils an amount of money to mitigate the impact of new development on an area.
Examples of contributions range from extra affordable homes and new open space, to funding of school places, or improving road junctions to deal with any extra traffic.
However, the funds have a time limit and "lapse" if they not spent by the Council within the appropriate time. Since 2012, £197,158.65 of funding has lapsed as unspent by Merton.
Adrian Hyyrylainen-Trett, Merton & Wandsworth London Assembly Liberal Democrat candidate said:
"Labour council bosses are always going on about how they run Merton in a 'business-like' way - but most businesses can't afford to waste nearly £200,000. It's scandalous.
"Merton should reveal why this money hasn't been spent. Over the last three years there's been £9.1million of planning compensation funds available to Merton, and yet so far only £3.3million has been spent.
"Residents deserve to know what the remaining £5.8million is going to be spent on, and when - so that we don't miss out on that too."
Adrian Hyyrylainen-Trett is the Liberal Democrat candidate for Merton & Wandsworth on the London Assembly.
Freedom of information request https://www.whatdotheyknow.com/request/information_on_s106_funds_16#incoming-784738