League president Lord Soper was also reported to be on the verge of resignation, as an escalating dispute threatened to tear the group apart.
Mr Barrington lost a no-confidence vote on the 12-strong executive last week. He was kept on but faced angry criticism from sections of the League's 40,000 members for appearing to "go soft" on hunting in a controversial article in The Field magazine. They were infuriated at a suggestion that the League would "feel less antagonistic" towards the sport if hunters ceased practices such as using terriers to root out foxes which had successfully gone to ground.
Mr Barrington, who claimed "constructive dismissal" as the reason for his departure, said he was forced to leave when the executive agreed on Wednesday night to reinstate a member of staff who he sacked.
"I find that situation to be untenable," he said. "My position has been undermined to a degree. This is part of a campaign. Indeed some people admit that is the way they wished to proceed, to make my job untenable so that I would have to go."
John Bryant, another leading member of the organisation, categorically denied the claims. "I do not recognise the situation Mr Barrington is painting," he told the same programme.
"There is absolutely no-one in the League who wants hunting to remain as cruel as possible to favour our campaign. We would welcome the abolition of certain aspects of fox hunting.
Mr Barrington had infuriated two-thirds of the staff by the "unfair and unlawful" dismissal of two colleagues for trivial offences and caused further aggravation by the article for The Field, he said.
League officials insisted that the 71-year-old organisation would survive, but acknowledged"huge internal conflict".Reuse content