After battling a rival bid, Transat A.T. (TRZ:CT) and Air Canada (AC:CT) now have one more thing to worry about. The gap between Transat’s share price and Air Canada’s takeover bid is sitting at the widest ever -- indicating investors aren’t confident the deal will get done.

Transat’s stock fell as much as 5.9 per cent Tuesday to $15.03, the biggest drop since early July. That’s nearly $3 below Air Canada’s offer of $18 a share or $720 million, which was raised earlier this month in an attempt to fend off an unsolicited bid from Quebec real-estate developer Group Mach Inc.

The tour operator’s shareholders voted 95 per cent in favour of the Air Canada bid last Friday. It’s now subject to other closing conditions, including approval under the Canadian Competition Act, the Canada Transportation Act and European Council regulations.

Canada’s transport minister Marc Garneau said Monday that officials need until May to review the proposed acquisition in order to ascertain whether the deal is in the best interest of the public.

The competition review is anticipated “to be the most strenuous given the overlap of the companies in Montreal and Quebec markets,” AltaCorp Capital analyst Chris Murray said in a recent note. “The upcoming federal election could also expose the transaction to heightened levels of political discourse, which could make regulators reticent to approve relevant reviews.”

However, Murray said he believes the deal will ultimately get the required approvals and will close by 2020.

Scotiabank analyst Konark Gupta agreed that the deal will eventually get done but added that the “Competition Act approval could be relatively more tedious compared to other regulatory and government approvals” due to substantial overlap between the two companies in sun destinations and transatlantic markets.

--With assistance from Divya Balji