The 11, including a former speaker, are being retried on a conspiracy charge related to the constitutional crisis of two years ago, which led to the toppling of the government.
Fourteen MPs were convicted in late 2015 after being found to have received money to cross the floor of parliament and change the government.
One of the MPs, Marcellino Pipite, who was parliament's speaker at the time, followed that up by using his powers as acting president to pardon himself and the others.