The architect of tough benefit reforms in Britain will face a picket by Sue Bradford's Auckland Action Against Poverty when he delivers a lecture in Auckland tonight.

Iain Duncan Smith, a former Tory leader and now a Cabinet minister, is speaking at the Maxim Institute's annual Sir John Graham Lecture at the Heritage Hotel.

Ms Bradford, a former Green MP, said Mr Duncan Smith's "horrendously damaging" welfare reforms in Britain, which include cutting housing benefits for thousands of low-income families, inspired many of the proposals by economist Paula Rebstock's Welfare Working Group in NZ. Government decisions on the Rebstock report are expected before this year's election.

Britain has already adopted many of the welfare reforms recommended in the Rebstock report here, including shifting all beneficiaries on to a single benefit with a standard clawback rate as they work more hours.

The rate is proposed at 55c for every extra dollar earned in the Rebstock report and in a similar report by Mr Duncan Smith's Centre for Social Justice think-tank, but is being legislated in Britain at 65c.

Mr Duncan Smith's Welfare Reform Bill, now before Parliament, would also make sole parents look for part-time work when their youngest child turns 5. The Rebstock group said they should look for part-time work when their youngest children turned 3 and fulltime work when they turned 6.

Mr Duncan Smith said other countries across Europe and North America were looking at similar reforms. "I think we're a little bit further ahead."

Britain had to act radically to cut its huge deficit. "Otherwise the markets will do to us what they're doing to Portugal and Greece."