Theresa May has rejected a claim by Labour leader Jeremy Corbyn that she is overseeing a "shambolic Tory Brexit".
During Prime Minister's Questions she said she wanted "maximum possible access" for the UK to the single market after leaving the European Union.
Mr Corbyn said the government had "no answers", but Mrs May promised to be "ambitious" in Brexit negotiations and to exert greater migration control.
But several senior Tories demanded more clarity about the UK's aims.
During a debate on a Labour motion about Parliament's role in Brexit policy, former business minister Anna Soubry said MPs must consent to the process of the UK's separation from the EU while Clare Perry said confusion about the UK's future access to the EU single market was having an alarming impact on the pound.
"The problem is that many people in the country don't think that there is a policy to put the national interest first, they think there is a policy to put people's narrow ideological interests first," she said.