After Palpatine's kidnapping, he immediately returns to the Senate and announces the establishment of Regional Governors across the galaxy. However, this ia a move not welcomed by many Senators since the orders for the governors comes directly from Palpatine - not the Senate.
Two influential members of the Senate decide to act against the Chancellor. Senator Bail Organa and Senator Mon Mothma decide to pull together the Star Systems that are opposed to Palpatine's new dictatorship.
One influential senator that is mentioned is Senator Amidala of Naboo. However, Bail and Mon Mothma, and other senators, are unsure whether or not she is to be trusted. Her alignment with Palpatine's home planet of Naboo is a cause of concern to them.
They decide to have a meeting with Senator Amidala where Amidala discusses the move against the Chancellor. After a short while, Amidala agrees to join their cause.
EDIT: Ternian also said:
They meet in Bail's Office. We aren't up to Padme's Senatorial meeting yet.
EDIT: About Mon Mothma:
Mon Mothma appears to be friends with Bail. As soon as the Regional Governors Act is enforced, she begins her rebellious ideals.
EDIT: About Padme:
You have four reports on Padme - this is the first.