The news follows a statement, released by the supermarket chain yesterday, which slammed the publisher 'for attempting to hold children to ransom by hiking up the RRP [£17.99] on the final Harry Potter instalment'.
A Bloomsbury spokesman said: 'Unfortunately, we've now had to initiate a significant libel claim against them. That matter will have to be dealt with [before their order is reinstated]. The ball is in their court. If they want their books, they will have to come and make peace with us.'
Earlier today, Bloomsbury cancelled an order to supply 500,000 copies of the final Harry Potter instalment to grocer Asda because of invoicing issues. However, Asda has rubbished the claims and said it is in talks with its legal team about addressing the order cancellation.
Asda confirmed that it has received the legal letter from Bloomsbury. However, it said: 'If they don't supply us with the books, it will have a massive implication. I don't think they will do that.'