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
The memorial service will be attended by Prince Harry and Meghan Markle.
David Browning admits manslaughter by diminished responsibility but denies murder.
Four people have died and the suspect is still at large, police said.