Labour will "hound" Iain Duncan Smith over welfare reforms, the new shadow work and pensions secretary has promised.

Owen Smith also said he would ask "tougher questions" of landmark pension reforms passed under the coalition.

And in an apparent dig at former interim leader Harriet Harman, Mr Smith said the Welfare Bill's passage through the Commons was "no time for abstention".

Ms Harman's decision to whip Labour MPs to abstain on the Bill's second reading was seen a key turning point during the leadership contest.

Mr Smith told the Labour conference in Brighton: "On the incompetent roll out of universal credit, or the scandalous impact of the work capability assessment, or the ongoing crisis of youth unemployment, you can rest assured I will be up and after Iain Duncan Smith like our animal-loving Prime Minister after an Oxfordshire fox.

"Because he deserves to be hounded for the way he has treated so many disabled people in our communities."

Mr Smith hit out at "demeaning" fit for work tests and the "desperate, awful" bedroom tax.

He added: "Under Jeremy's (Jeremy Corbyn) leadership we'll be fighting harder than ever to put an end to it.

"For Iain Duncan Smith, none of these measures are really about saving money, they're about being seen as tough, cutting the role of the state and playing politics.

"But he's got to learn that you can't play politics with people's lives conference. And I won't let him."