Julia Gillard's cabinet has been leaking. Most recently, such leaks puprorted to reveal a split among ministers over asylum seeker policy, following the collapse of her Malaysian Solution. Such disagreements aside, leaks themselves are a sure sign of government instability.
Cabinet solidarity is one of the essential characteristics of the Westminster system of government. Furthermore its central feature is common to all expressions of collective leadership because it enshrines virtues like unity and teamwork.
Cabinet solidarity operates alongside associated concepts like cabinet secrecy, which protects official documents like papers and minutes from publication, and collective ministerial responsibility. These guiding rules make cabinet discussions sacrosanct, assisting the whole team to work together.
Solidarity and unity are understood by most groups, including trade unions, political parties and pressure groups, as necessary for success. Slogans like 'In unity is strength' and 'Solidarity forever' sum them up. That is why disunity and breaches of solidarity are taken seriously.
Importantly the concept does not mean cabinets should not have private disagreements about policy before, during and even after decisions are made. Unity does not mean uniformity. That would be both unrealistic and unhealthy. But disagreements should not be public.
In berating her ministerial colleagues the Prime Minister has rightly pointed out that if the system is working properly there should be frank and fearless discussions within cabinet. What we know of past cabinets suggests discussion is often fierce and passionate.
But solidarity means that eventually the team must come first. If a team member has such strong feelings about an issue that they cannot accept the discipline that comes with cabinet solidarity, then they should resign their position. If they stay on and then break cabinet solidarity by speaking out against a cabinet decision then they can and should be sacked.
A cabinet decision, such as the Gillard Government decision to process asylum seekers onshore rather than explore the Nauru option, binds all cabinet members. There is one practical reason for this. Ministers have to defend the government's position in Parliament and in the community even if they disagree with the majority view.
That can be extremely uncomfortable. But cabinet solidarity means ministers can retain their dignity even if they are 'rolled' in cabinet, as they often will