Immigration Minister Chris Evans has reportedly said the immigration debate is "killing" the government and that the issue had become "toxic".

Sydney's Radio 2UE cited the minister as making the remark on today at a conference, which was closed to the media, hosted by the University of NSW.

It said the senator had told immigration experts at the event the debate was ‘‘killing the government’’.

The report also cited Senator Evans as saying controlling the debate on immigration had been one of his greatest failings as minister and that the issue had become toxic.