FILE PHOTO: EU Council President Donald Tusk holds British Prime Minister Theresa May’s Brexit letter which was delivered by Britain’s Polish special services consider threat of assassination attempt on Tusk and Minister of Defense real Key points and original sources are listed below.

• FILE PHOTO: EU Council President Donald Tusk holds British Prime Minister Theresa May’s Brexit letter which was delivered by Britain’sS1

• Polish special services consider threat of assassination attempt on Tusk and Minister of Defense realS2

• Government spokesperson tells Polish media 'the matter is serious'S3