The House of Representatives is holding a four-day special session to try to reduce its backlog of work before the end of the term in September.
The other parliamentary chamber, the Senate, is not sitting.
Among the main issues tabled are a proposal to give voters a greater say in international treaties.
A committee by conservative isolationist politicians collected enough signatures to force a nationwide vote on the issue. The initiative by the Campaign for an Independent and Neutral Switzerland was handed in 18 months ago.
The government has come out against the proposal, but put forward a compromise.
Parliament is also due to begin discussions on a number of revised double taxation agreements as well as controversial tax breaks for companies.
Centre-left parties have called for the result of a nationwide ballot in 2008 to be declared null and void after it emerged that the reform will lead to a multi-billion franc shortfall in revenue over several years.
They argue the government misled voters by forecasting an annual shortfall of just SFr50 million ($55 million).