UPDATED 6.04PM: New Zealand first MP Ron Mark is under attack for comments he's made in Parliament.

During a debate on Easter Trading legislation on Tuesday Mr Mark told National MP Melissa: "If you don't like New Zealand, go back to Korea."

Ron Mark's behaviour is being criticised across the board.  

His colleague Tracey Martin, who he replaced as deputy leader, didn't like the remark.  

"It's not a statement I would have made," said Ms Martin. 

ACT Leader David Seymour has demanded Mr Mark withdraw and apologise for the comments.  

Today as Mr Mark asked a question alleging security services were being racist by focusing on immigration Mr Seymour seized the opportunity to ask if racist attitudes generally could be classed as a security concern.

Minister Chris Finlayson retorted with this: "If for example, there was a sort of KKK group, not referring to anyone in this house, of course, that indulged in that kind of thing, then that could well be a security issue."  

Mr Mark has also been criticised by United Future Leader, Peter Dunne.  

Not everyone's offended though, another New Zealand First colleague, Pita Parone, wasn't offended.  

"It was said in the heat of the moment, as part of the theatre of Parliament."  

Mr Mark said he was responding to abuse he was receiving and refused to apologise for the comments.  

He said if people have the view he needs to grow up, then that's their view and they can move on.