The review, to be published on 25 November, will outline how the Government plans to eliminate the national deficit by 2020.
According to a blog post by a group calling itself Save Big Lottery, the Government needs to "save face" over slashing the budget of the Department of Culture, Media and Sport (DCMS). It plans to do so by diverting "good causes" money from the National Lottery that goes to BLF and give it to DCMS instead.
The expected cut in the share of "good causes" money - from 40 per cent to 25 per cent - would mean a reduction of £320m a year. It is not clear who is behind the Save Big Lottery website.
In the last two years the Big Lottery Fund has spent £835m (2014) and £891m (2015) on grants, including to charitable organisations such as Groundwork and many small community projects including parks and allotments across the country.
BLF has currently committed £10m of funding for public parks each year until 2018.