"hardly likely to" is correct and usable in written English.
It is typically used to express a low probability of something happening, such as "It is hardly likely to rain tomorrow."
The clash at lunchtime on Sunday at the Salford City Stadium, where Sale have moved this season from Stockport, is hardly likely to decide Pool 6, which also contains Toulon and Montpellier, but, curiously, it still holds an attraction.
The UK's regulator, the Information Commissioner, is limited to a maximum £500,000 fine, hardly likely to dent a company of Google's size.
A one-off £50bn drop is hardly likely to make much of an impact.
His chance of winning was hardly likely (he wound up shooting a 73 to finish nine strokes off the lead).
Either way, expecting people to live and work illegally for 10 years is hardly likely to spark a further wave of illegal migrants.
Especially, if one of the EU members gets 'agenda setting power', it is hardly likely that a Union with heterogeneous 28 members would achieve collective action (Olson, 2002).
And '(s)ince as a practical matter it is never easy to prove a negative, it is hardly likely that conclusive factual data could ever be assembled.' Elkins v. United States, 364 U.S. 206, 218, 80 S.Ct.
It seems hardly likely that the health cost would be approximately SEK 1,000 per year and person at 67 dB but SEK 0 at 66 dB.
So the fact that they were missing Asafa Powell, because of the groin strain he suffered in the 100m final last Saturday, was hardly likely to hamper them much.
Near as Mars will be this week, 34,646,418 miles away, observers are hardly likely to see as much as their imaginations once could see.
This year's Electra Glide sports the company's new Twin Cam 88 engine, but that's hardly likely to generate complaints.
