The Prime Minister's letter officially notifying the European Council of the UK's intention to quit will set in train a two-year negotiation process expected to lead to Britain leaving the EU on March 29 2019.
Prime Minister Theresa May will trigger Britain's withdrawal from the European Union under Article 50 of the EU treaty on March 29, her spokesman said on Monday.
Notification comes 279 days after the referendum of June 23 past year delivered a 52 to 48 per cent majority in favour of withdrawal.
Dr White said the Bills, dealing with issues such as immigration procedures, would be on top of the Great Repeal Bill, which will incorporate European Union law into British law.
Analysts at City Index said: "In fairness, we think that today's dip in the pound is just a knee-jerk reaction to the Article 50 news, and part of sterling's decline is also due to the recovery in the dollar and US Treasury yields".
Tusk will receive another letter from May on Wednesday next week to invoke Article 50 before she provides a statement to MPs in Parliament.
The Prime Minister is attempting to reach out in order to address criticisms that she is not paying proper attention to different administrations.
He said the Government wanted to secure "a new, positive partnership between the United Kingdom and our friends and allies in the European Union".
Mr Tusk said recently that European Union leaders would respond within "more or less 48 hours" of the letter, starting possibly the most complicated series of negotiations in British history.
The formal process is expected to take two years according to an official table setting out deadlines, which - if stuck to - would see the United Kingdom officially become autonomous in 2019.
The notification of triggering Article 50 will come in the form of a letter delivered to Tusk next week, which will likely plunge Britain into a period of intense uncertainty.
"I hope for realism on the sequence of things, realism on the price that it is going to cost, realism on the complexity and thus the timespan that will be necessary, because those are the things that I have missed so far from the British side", he said.
EU leaders have said they want to conclude the talks within 18 months to allow the terms of the UK's exit to be ratified by the UK Parliament and the European Parliament, as well as approved by the necessary majority of EU states.
The government has indicated that Britain could make contributions to the European Union budget to ensure trade access. Leaving the Single Market was not on the ballot paper in the referendum, it is a political choice made by Theresa May.
London has repeatedly said it wants to maintain good relations with its European allies, but major battles await, in particular over budget contributions, immigration and future trade ties. Mrs May is not attending the event.