Not sure if this is national but Asda in York are doing kids eat free with a £1 spend (Takeaway Only). They can choose either a hot or cold meal.
All meals come with a piece of fruit and a drink included. There is a minimum spend of £1 in the café regardless of the number of free kids meals provided in a single transaction. The children do not need to be in attendance for the promotion to be valid and it is limited to one free meal per child per day. All meals will be provided for takeaway only to comply with current guidelines