Double dissolution

In Georgeland politics, the term "double dissolution" is used to refer to simultaneous dissolution of both the House of Commons and the Senate as part of a general election.
Under normal circumstances, a general election elects the entire House of Commons and one-half of the Senators. Under Georgeland's constitution, while the President issues the writs for a Commons election (officially dissolving the House), the Senate writs are issued by the State Governors. Only one-half of the Senate seats in each state are declared up for election every three years, as Senators serve six-year terms.
However, under a double dissolution, the President is empowered to issue writs for the dissolution of the entire Senate, when, and only when, a very specific set of circumstances occur. Specifically, the President may take this action when:
1. Legislation has been rejected by either House of Parliament, and, after being re-introduced (after first being sent to the relative parliamentary committees for adjustment), is rejected by either House again (regardless of which House rejected it the first time).

This is the most common type of double dissolution. Elections of this kind have been held 7 times - in 1935, 1954, 1973, 1987, 1995, 2002 and 2005. In all cases but one, the Senate rejected legislation both times, usually as a result of a lack of government control of the Chamber. In 2002, while the Senate defeated the government's Cloning and Stem Cell Research Act the first time, it was subsequently defeated in the House of Commons before reaching the Senate. This was the first time a Commons rejection of legislation had triggered a double dissolution. Though constitutional, it was considered unorthodox as the Senate had not rejected the legislation. Charlton Robards, Prime Minister at the time, has repeatedly stated there would have been a dissolution in any case, as the Senate was "highly unlikely" to have passed the bill even if the Commons had.
This type of double dissolution is only ever called on the exclusive advice of the Prime Minister and the Cabinet. The President is not empowered to call it without this advice, in writing.; or

2. An "irrepairable breakdown of government has occurred".

This type of dissolution has occured only once, in 1999. It is called when no party controls the House of Commons and there is no clear choice for Prime Minister, or when Parliament has acted unconstitutionally. In 1999, when Charlton Robards was defeated in a leadership challenge but refused to resign, and later took his supporters out of the Labour Party, President Susan O'Byrne invoked the President's reserve powers and acted to declare Parliament dissolved and hold fresh elections. While this power was invoked without the approval of Cabinet, it was not unilateral, as many have suggested. O'Byrne did, in fact, recieve this advice from Robards, who was still legally Prime Minister (his commission was not yet revoked), but she did not follow it initially, instead revoking the commission, appointing Michael Fisch as caretaker Prime Minister. Fisch then advised O'Byrne to call an election, which she did.
This remains the only time this power has been used, and this type of dissolution has occured.