BBC Scotland understands that a deal was agreed between the two parties.

But Falkirk have offered McCall a much-improved deal to stay at the club.

Falkirk have called a news conference for 1245BST on Wednesday.

United announced the dismissal of Alex Smith after just over two years as boss on Monday.

Thompson confirmed to BBC Scotland on Tuesday morning that McCall was the man he wanted to take over from Smith at Tannadice.

But the Falkirk board have twice turned down Thompson's request for permission to speak to McCall, who is in the first year of a two-year deal at Brockville.

Nevertheless, Thompson stressed that he would go to great lengths to get his man.

"I'm not the kind of person who will walk away if I'm interested in someone," said Thompson.

"The word I'm getting through is that McCall is definitely interested in joining Dundee United.

"I'm sure if we sat down, if allowed to, I could convince him that Dundee United are a club that can move forward and take Ian McCall with us."

"What I'd like to do is to get a manager in well before then so that he gets to know the players and the style and everyone at Tannadice," he added.

"I'll be working over the next few days to bring Ian McCall to Tannadice."

Former Clydebank, Morton and Airdrie boss McCall has steered Falkirk to the top of Division One, winning seven of their opening nine games and only losing once.

The Bairns have made it clear that they will fight to hold on to their man.

A statement from Falkirk chairman Campbell Christie was posted on the club's website.

It read: "We were approached by Dundee United this afternoon (Monday) and I have spoken to their chairman.

"I have made our position clear. Ian McCall has committed himself to Falkirk FC for two years and we want him to remain with the club."

Thompson said on Monday he was looking for a "bad loser" who would bring "fight, vigour and excitement to Tannadice".

McCall certainly fits that bill. Inverness Caley Thistle boss Steve Paterson has also been mentioned as a candidate and may be a fallback if the bid for McCall fails.

Former Rangers and Everton boss Walter Smith and ex-Dundee United and Rangers defender Richard Gough have also been linked with the vacancy.

United plummeted to 11th place in the Premier League table following their defeat at Hibernian on Saturday.

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