Ally McCoist last night described Charles Green as an "embarrassment" and vowed not to be intimidated by "a threat" from the club's former chief executive.

Green has returned to Rangers in a consultancy role, two months after having to step down following revelations about his involvement with Craig Whyte, the former owner who put Rangers into administration.

In a newspaper interview yesterday, Green said that McCoist would face problems if he did not win the league and a cup, and repeated his assertion that last season's team was the worst in the club's history.

McCoist responded bluntly. Their relationship broke down last season when Green attempted to undermine him by threatening to sack his assistants, Kenny McDowall and Ian Durrant. Green also identified a replacement manager, and McCoist did not hold back in responding to Green's comments following his side's 2-1 defeat to Forfar in the League Cup.

"If it was a threat, the self-acclaimed, straight-talking Yorkshireman should know that boys from the west of Scotland don't scare easily," McCoist said. "If he does come back, I'll certainly go and pick him up at the airport. I won't have a problem doing that.

"It's more hot air and that's what we've come to expect from Charles. He just seems to be a devious man. I was appalled by Charles's comments. The so-called, self-acclaimed straight-talking Yorkshireman again let himself down. He's an embarrassment."

Green deliberately challenged McCoist. He will have calculated that a period of unrest and tension with the manager might prompt a resolution to the battle for control in the boardroom and among the shareholders. On the day of Green's return, it was revealed that a group of shareholders, led by Scottish businessman Jim McColl, had sent a notice requisitioning an extraordinary general meeting.

It calls for the removal of Brian Stockbridge, the finance director, Craig Mather, the chief executive, and Bryan Smart, the non-executive director, and the appointments of Paul Murray, the former Rangers director, and Frank Blin, the former PriceWaterhouseCooper executive, to the board.

The battle could be brutal, and McCoist felt that Green's comments had caused a negative reaction amongst his players.

"His contempt and total lack of respect for my players, this football club and our support and Scottish football in general is appalling," said the Rangers' manager. "I've got to be careful because Forfar deserved their win and well done to Dick Campbell and his players. But our players picked up the newspaper at breakfast to be reminded they're the worst team in Rangers' history.

"I'll tell you, that would be bad luck - to have the worst Rangers team in history and the worst chief executive in history at the same time. Instead of concentrating on the match, their minds are elsewhere and they're worrying about their jobs. He's said some of the players would be under threat too.

"I don't think it's surprising that it's when we're probably at our most vulnerable and weakest because we can't play our new signings that Charles has surfaced. The biggest thing of the lot is that he's turned up after 34,000 fans have bought season tickets. Coincidence? Perhaps not."