The Business Secretary Vince Cable has said that it is not sensible to deal with UKIP by "insulting" or "ignoring" them.
He told Sky News' Murnaghan programme: "I think it's very important that UKIP are subject to the kind of scrutiny that we are subjected to and other major parties.
"It's absolutely right, I have never believed that it's sensible to deal with Ukip by insulting them or ignoring them.
"They are a force at the moment and they should be subject to scrutiny and subject to debate, let's try and find out what their policies are, it isn't terribly clear."
More top news
A father has been sentenced to life in prison after being convicted of intentionally leaving his toddler son to die in a hot car.
Theresa May has refused to rule out paying money to the EU after we leave, so that UK firms can still trade with the single market.
Relatively low levels of drinking may trigger potentially dangerous irregular heartbeats, new research has found.