The Scottish Conservative Party leader Ruth Davidson has called on politicians to stop being overoptimistic about Brexit and urged "serious people" to take charge of negotiation with the European Union (EU).
The Tory politician, a remain campaigner, said that the complexity about Brexit is not something people in charge should "just skip over".
"I think optimism, positivity is good," Davidson said during an interview with The Times.
"I think over-optimism and not recognising that there are practical realities that have to be faced, that have to be worked through and that complexity is not something you just skip over, that you actually have to work through, I think sells people short."
Some believe that Davidon's comments refererred to the fact that Foreign Secretary Boris Johnson said last month that Brexit would make the UK "the greatest country on earth".
He also claimed that the UK will save £350m every week once it leaves the EU, suggesting that a large sum of this money should be spent on the NHS.
Davidson denied the comments are related to Johnson's remarks.
"This needs serious people to do a lot of legwork and scanning the detail to make sure we do get to a place where it will all be okay," she said.
Davidson's comments came as Johnson said that a transition would not last longer than two years after the UK officially leaves the EU in 2019. He also said the that the UK should not accept new rules from the EU during the transition.
Prime Minister Theresa May said during a conference in Florence that the transition period would be of "about two years". However, some remainers are pushing for a transition of up to three years.
Speaking from Estonia, where she attended an EU security summit, May said she was pleased as progress had been made on the rights of EU citizens, but she did not add when the next phase of negotiations will begin.
European Commission President Jean-Claude Juncker said trade talks would only commence next month if "miracles happen."