The Government's Operation Yellowhammer contingency plan to handle a no-deal Brexit is being "triggered", Michael Gove has said.
The Chancellor of the Duchy of Lancaster, who is in charge of preparations for a no-deal outcome, said the risk of such a scenario had increased due to MPs forcing the Government to ask Brussels for another delay to the Brexit date.
Some Westminster observers viewed the move as a bid to increase pressure on MPs to back Prime Minister Boris Johnson's Brexit deal.
Mr Johnson has insisted the UK will exit the bloc as scheduled on October 31, and said he will present the Withdrawal Agreement Bill to Parliament in the coming days.
Mr Gove told Sky News: "The risk of leaving without a deal has actually increased because we cannot guarantee that the European Council will grant an extension.
"And that is why I will, later today, be chairing a Cabinet committee meeting, extraordinarily on a Sunday, in order to ensure that the next stage of our exit preparations and our preparedness for no-deal is accelerated.
"It means that we are triggering Operation Yellowhammer.
"It means that we are preparing to ensure that, if no extension is granted, we have done everything possible in order to prepare to leave without a deal."
Secret documents that MPs forced the Government to release last month said a no-deal Brexit could lead to rising food and fuel prices, disruption to medical supplies and public disorder.
The Government said the Operation Yellowhammer "planning assumptions" were a "worst-case scenario".
The plan includes dealing with the risk of border delays.