LONDON (AP) — British Prime Minister Theresa May is seeking to reassure European Union leaders that her Brexit timetable remains intact despite an adverse court ruling.

She plans to telephone European Commission President Jean-Claude Juncker Friday to spread the word that her plan is still to start the process to remove Britain from the EU by the end of March.

May's ability to invoke Article 50 to formally begin the process may be slowed, however, by a High Court ruling that the government needs Parliament's approval first.

The government plans to appeal this ruling to the Supreme Court with a hearing expected next month.

The prospect of parliamentary involvement has raised the prospect of delays in the Brexit process and also the possibility of an early general election in Britain.