Story highlights Brexit bill passed UK Parliament earlier this week

PM May expected to trigger Article 50 before end of March

London (CNN) Britain should stop threatening the European Union ahead of the Brexit negotiations, a top EU official has warned.

Donald Tusk, President of the European Council, said the EU would not be "intimidated" by threats from Britain that it would prefer to walk away from Brexit talks if it did not get its way.

British Prime Minister Theresa May is expected to trigger Article 50 by the end of this month. That would allow formal negotiations to begin between the British government and the 27 member states on the terms of the UK's exit from the EU.

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"It is our wish to make this process constructive, and conducted in an orderly manner," Tusk said in a statement to the European Parliament.

"However, the claims, increasingly taking the form of threats, that no agreement will be good for the UK, and bad for the EU, need to be addressed.

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