Yusuf said his party had pledged to "resist" housing asylum seekers in Reform-controlled areas and it would use "every instrument of power available", including judicial reviews, to fulfil its pledge.
"The levers of power at a local level pale in comparison to the levers of power at Westminster," he told the BBC's Sunday with Laura Kuenssberg programme.
But he said "those levers of power will be pulled with all our might by Reform councillors," adding: "There are things you can do, there are judicial reviews, there are injunctions... things around planning, budget allocation."
He told Laura Kuenssberg: "A lot of these hotels... you suddenly turn them into something else which is essentially a hostel that falls foul of any number of regulations - that's what our teams of lawyers are exploring at the moment."