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The admonishment comes two days before she seeks a fourth term in power in Sunday's general election - with 20 percent of voters still undecided who they will support. The report by the Bundestag Scientific Office - a team of non party political legal experts - stated it is the role of the Bundestag to decide on all "matters of essential relevance to the state". Experts said the opaque diplomatic language used in it signals parliament should have had the final say on the matter "as the decision led to a change in the proportion of non-Germans to Germans in the country".

EPA•GETTY German election 2017: A report appears to condemn Angela Merkel for her open door refugee policy

Influential news magazine Der Spiegel said: "Bundestag lawyers clearly see an unclear legal situation for the border opening. "This is an explosive opinion on the refugee crisis shortly before the election." The story was broken by the Die Welt newspaper. Merkel opened up the borders in September 2015 after discussing the issue with her cabinet. Since then she has lost thousands of party members to the hard right Alternative for Germany (AfD) party and witnessed bogus asylum seekers carry out terror attacks.

German election: Photos from the election Mon, September 25, 2017 Latest pictures during the upcoming general elections in Germany Play slideshow REUTERS 1 of 22 Demonstrators scuffle with police during the protest against the anti-immigration party Alternative for Deutschland AfD, after German general election (Bundestagswahl) in Berlin

This is an explosive opinion on the refugee crisis shortly before the election Der Spiegel

To this day she has never explained the legal basis for arriving at the decision which will see the AfD become the main opposition party in a new parliament even though she is still expected to win. The internal report says German law states that refugees do not have a right to apply for asylum in Germany if they entered the it through another signatory to the 1951 Refugee Convention. They said, according to German law, asylum seekers should have been turned away at the Austrian border.

REUTERS German election 2017: The admonishment comes just two days before she seeks a fourth term in power