WARSAW, Poland (AP) — A Polish appeals court has ruled that Lech Walesa, a former president and pro-democracy fighter, must apologize to the head of the ruling party, Jaroslaw Kaczynski, in a slander case.

Walesa protested the verdict by the Appeals Court in Gdansk on Monday and said he would take it to the Supreme Court and even to the European Court of Human Rights in Strasbourg.

Kaczynski, the head of the ruling Law and Justice party and Poland's most powerful politician, sued Walesa for blaming him on social media for the 2010 plane crash in Russia that killed Kaczynski's twin, President Lech Kaczynski, and 95 others.

In one of his posts, Walesa alleged that Kaczynski, was "guided by bravado" and over the phone was pushing for the plane to land despite heavy fog.