British Prime Minister abused his powers by seeking to suspend parliament from next week until shortly before Britain leaves the European Union, London's High Court was told on Thursday.

Johnson announced at the end of August that he would suspend parliament from mid-September to mid-October, just before Britain is due to exit the European Union on Oct. 31, to allow the government to announce a new legislative programme.

At a hearing at the High Court, David Pannick, a lawyer, representing the campaigner Gina Miller, said in the last 40 years parliament had never been suspended for so long.

Pannick said comments from Johnson showed that an important part of his reasoning was that parliament might say or do something that impeded the government's Brexit plans.

"It breaches the legal principle of parliamentary sovereignty," he said. "What the prime minister is not entitled to do is to close parliament for five weeks at such a critical time without justification."

Pannick said the case was not about whether Britain should leave the EU or on what terms, nor was it a criticism of Queen Elizabeth who agreed to the government’s request for a suspension.

Miller, the campaigner who mounted a successful legal challenge to Prime Minister Theresa May’s government over its authority to leave the EU without a vote in parliament, is seeking a judicial review.

Her case is supported by former Conservative Prime Minister John Mayor and Shami Chakrabarti, the opposition Labour Party's top legal adviser.

A Scottish court ruled on Wednesday that Johnson's decision the matter was not one for judges to decide. A similar legal bid in Northern Ireland will be heard on Friday.