Mr Miliband, 47, will host the current affairs show on the week of June 19 and fellow MP Mr
Duncan Smith, 63, kicks off his five day-stint on June 26.
Mr Crabb, who is MP for Preseli Pembrokeshire, will take over the role after Mr
Duncan Smith suddenly resigned on Friday over proposed cuts to disability benefits.
Smith previously met
Duncan Smith and explained the problems faced by some of the most vulnerable people in Easterhouse.
Mr
Duncan Smith might have got more brownie points if he had not tried so hard to conceal it.
In 2011, Mr
Duncan Smith's department ordered Miss Reilly to take on two weeks of unpaid shelf stacking at a Poundland in Birmingham, forcing her to give up her voluntary work at a museum in the process.
Until 2001 the mansion was home to Mrs
Duncan Smith's father, Commander John Tapling Fremantle, 87, the fifth Baron Cottesloe.
The intervention came amid reports that the Chancellor and Mr
Duncan Smith had a blazing row over the up-front costs of proposals for reforming the benefits system.
Mr
Duncan Smith said: "If you don't get a grip of the gang culture, you will have guns here inside two years."
But a spokesman for Mr
Duncan Smith described it as "a very positive meeting".
Mr
Duncan Smith said the allegations had put his wife through ``all shades of hell'', while she said she was looking forward to putting a ``terrible time'' for her family behind them.
The committee said Mrs
Duncan Smith should have been paid in part out of "Short money" - given to opposition parties - rather than her husband's parliamentary staffing allowance.
Glyn Davies, AM for Mid and West Wales, said Mr
Duncan Smith could not provide effective opposition to the Government and predicted the party's fortunes would improve with Michael Howard as leader.