The Tesco Charity Trust Community Awards Scheme provides one-off donations of between £500-£4000 to local projects that support children and their education and welfare, elderly people and adults and children with disabilities. It might be worth investigating if your Playday event or wider campaigning would fit this criteria.
The grants programme will open for applications will open from the 1st December 2009 to the 31st January 2010.
More information about Tesco Charity Trust
here