The School Funding (Wales) Regulations 2010

36.  Junior class sizes limited to a maximum of 30 pupils: the authority may include a sum which reflects any increase in expenditure incurred as a direct result of conditions contained in any special grant made in accordance with section 88A of the Local Government Finance Act 1988 or any arrangements for financial assistance provided in accordance with section 14 of the 2002 Act which requires an improvement of school standards by reducing class sizes.