Merkel repeated her warning on Monday that there could not be any Brexit negotiations based on the UK "cherry picking" parts of the EU it prefers without accepting the “four freedoms”-- the free movement of goods, capital, services, and people.
"Access to the single market can only be possible on the condition of respecting the four basic freedoms. Otherwise one has to talk about limits to access," Merkel said at a meeting of the German Civil Service Federation in Cologne.
"These negotiations can not be based on cherry-picking because that would have disastrous consequences for the other 27 member countries."
The German chancellor made the comments after British Prime Minister Theresa May defended her government's approach to Brexit negotiations.
May told Sky News on Sunday that Britain would not be retaining "bits" of its EU membership after Brexit, suggesting that Britain will end up withdrawing from the single market and then trying to quickly negotiate a free trade deal with the EU.
Of the four freedoms, the freedom of movement is perhaps the most contentious, especially in Britain.
Retaining access to the single market has been one of the major worries for UK businesses ever since the country voted to leave the EU in a referendum on June 23.
May has said she will invoke Article 50 of the EU's Lisbon Treaty, a two-year process for leaving the bloc, by the end of March.
However, a High Court ruling in November said the government did not have the authority to trigger Article 50 without parliamentary approval.