Tory leadership candidate Liz Truss has pulled out of a BBC interview saying she "doesn't have time".
Ms Truss was due to sit down with Nick Robinson for a grilling, which was due to air on BBC One on Tuesday at 7pm.
But her team told the BBC that she no longer had the time to appear on 'Our Next Prime Minister'.
Mr Robinson said he had been left "disappointed and frustrated" that she pulled out of the interview.
Shadow Minister Conor McGinn accused her of trying to "avoid any public scrutiny whatsoever".
"People will rightly conclude that she doesn’t want to answer questions about her plans for the country because she simply hasn’t got any serious answers to the big challenges facing our country," he said.
A source from Mr Sunak's team said: "Avoiding that scrutiny suggests either Truss doesn't have a plan at all or the plan she has falls far short of the challenges we face this winter."
In a statement, the BBC said: "Liz Truss has cancelled her BBC One interview with Nick Robinson which was due to air this Tuesday evening (30 August) at 7pm. Ms Truss’ team say she can no longer spare the time to appear on “Our Next Prime Minister”.
"The other candidate for the Conservative leadership, Rishi Sunak, was interviewed by Nick on 10 August.
"We regret that it has not been possible to do an in-depth interview with both candidates despite having reached an agreement to do so."
Mr Robinson later tweeted: "Was pleased to secure an in-depth interview with @trussliz on BBC1. I am disappointed & frustrated it’s been cancelled."
It comes as the Government has been paralysed as energy bills soar, prices spiral and real wages are hammered, as Tory leadership hopefuls Ms Truss and Rishi Sunak battle to succeed lame-duck Prime Minister Boris Johnson.
Viewers would have been eager to hear from Ms Truss, especially regarding her plans to cut taxes.
Ms Truss is understood to be focusing on tax cuts and boosting productivity, before looking at what further support is needed for households facing a cost of living catastrophe this autumn.
The likely next PM is said to be considering slashing VAT by five per cent - which could cost £39billion - as well as income tax cuts, as she prepares for victory in the Tory leadership race.
Ms Truss has already vowed to axe the National Insurance hike that came into effect in April and to scrap a planned rise in corporation tax.
Her team insist she isn't ruling anything out but she has signalled her reluctance to offer immediate direct support to households - such as the £400 energy bills discount Brits will receive this autumn.
It comes as the Foreign Secretary is under intense pressure to set out her plans to help struggling Brits amid widespread expectations she will win the Tory leadership race in September.
She has promised "decisive action" if she wins, with an emergency Budget expected next month as households brace for calamitous hikes to their energy bills in October.c
But Ms Truss, who has previously dismissed “handouts” for hard-hit families, is expected to favour tax cuts over universal support on bills.
Her allies insisted she hasn't taken anything off the table after the BBC reported sources saying she had "ruled out" further direct support, like the £400 payment all households will get this winter.