The Prime Minister’s comments came amid reports that Bank of England governor Mark Carney is pushing for firms to retain access to the single market for two years after Britain leaves the European Union to smooth the transition to any new arrangement.
Mrs May said there were “really complex issues” at play in the process of leaving the EU, telling the Sunday Times: “In this job you don’t get much sleep.”
Asked “what are your biggest anxieties, what keeps you awake at night?” the Prime Minister said the country was facing a “hugely challenging time” following the Brexit referendum vote.
She said: “Well, it is a moment of change. It is a hugely challenging time. And we need to get on with the deal in terms of Brexit. And I’m very conscious of that.
“I want to make sure that everything we do ensures Britain is a country that works for everyone. And that we really get out there and forge a new role in the world post-Brexit. We can make a success of it, we will make a success of it.
“But these are really complex issues.”
Mrs May was asked how she prepared for taking tough decisions. She said: “It’s not so much about how do you steel yourself, it’s about, ‘Are you doing the right thing?’ If you know you are doing the right thing, you have the confidence, the energy to go and deliver that right message.”
The Sunday Times reported that Mr Carney has floated the idea of an extended transition period in meetings and dinners with City figures.
The newspaper said he hosted a dinner last Monday at Chatham House for about 50 senior investment bankers and a second on Wednesday for finance directors of the high street banks.
“Carney knows there needs to be a two to three-year extension to allow Britain to adjust from the old rules under Europe to the new order. His key word is continuity,” said a banker who attended the Chatham House dinner.
At the CBI conference last week Mrs May acknowledged the concerns of businesses about a sudden “cliff edge” change in the trading relationship with Europe after Brexit.
But Eurosceptics will resist any move they see as attempting to stretch out the Brexit process beyond the two years of the Article 50 process.