Signing off he promises to have dinner with him soon when he will "bring a blank cheque". "This letter is further evidence of the appalling trouble Dickens had with his father who was very reckless financially," Michael Slater, a Dickens' expert, said.
"By 1841 Dickens was so exasperated that he told Mitton to put an advert in all daily newspapers saying he would not be responsible for any debts incurred by his father," he said.
"But this letter does show that was not the case privately and also shows how bothered Dickens was by his father's debts," he said.
"Clearly Dickens had been expecting to pay but was surprised by how much money Mitton had given his father without him knowing. He is saying in the letter what a fool he is," Slater said.
Despite their strained relationship, Dickens and his father remained on good terms and the novelist even used him as inspiration for the character Mr Micawber in his 1850 work David Copperfield. The letter has emerged after being put up for sale at auctioneers Bonhams by a private collector.
"The fact that the letter is newly discovered and unpublished is very exciting and makes it extremely desirable," Francesca Spickernell, from Bonhams, said.
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