Prime Minister Boris Johnson could have to legislate for direct rule in Northern Ireland if the UK leaves the EU without a deal.
Foreign Secretary Dominic Raab, effectively Mr Johnson's deputy prime minister, said legislation would need to be considered if there was a no-deal Brexit so there would not be a "vacuum" in Northern Ireland.
Leading think tank, The Institute for Government (IfG) has recommended that legislation would need to be in place for the introduction of direct rule "given the scale and the speed of the interventions likely to be necessary" in the case of a no-deal exit.
The IfG added: "This will be extremely contentious, but without it Northern Ireland will be left even more exposed to the economic shocks of a no-deal Brexit than it is currently. That would itself raise the risk of all political backlash."
Asked whether direct rule could be done without legislation, Mr Raab told BBC Radio 4's Today programme that the question is "the extent to which it can be done".
He added: "What I'm saying is we will make sure the arrangements are in place to make sure all the risks across all quarters of the United Kingdom, but particularly in relation to Northern Ireland, can be addressed and managed in as sensible and as smooth a way as possible.
"And we are mindful, of course, of the sensitivities in Northern Ireland. The number one thing we have made clear is there will be no return to a hard border and no extra infrastructure."
PM Boris Johnson is expected to visit Northern Ireland in the near future following the announcement of an extra £300m of investment in parts of Northern Ireland, Scotland and Wales.
However, speaking outside Stormont, Sinn Féin's deputy leader, Michelle O'Neill, said direct rule would be "unacceptable".
"Direct rule is not acceptable and we're not going backwards," she said. "We can only go forwards.
"The St Andrew's agreement removed the ability for the British government to go backwards and to roll back on direct rule. So it's not acceptable to me and it certainly wouldn't be acceptable to the Irish government, I would expect also."