(or why the government cant damage RNLIs service delivery)
The government it gradually trying to takeover the voluntary sector. Charitable organisations are being sucked into dependency on the public sector.
Personally I find this highly objectionable - charity is an opportunity for individuals to 'do good' for others of their own free will. It is also an opportunity for people to make their own choices about what they want to support, allocating their own money(/time) according to their own principles and beliefs.
Government involvement debases the whole setup - stealing the opportunity for the individual to do good and replacing it with an obligation to support whatever the Government decides is worthy.
If the government is to take on a responsiblity then it should do so properly, funding it fully from taxation, paying market rates (no more, no less) for the resources it consumes in providing the service - whatever it happens to be.
Decisions are tough when you know many people will disagree with them - but let people make their own choices and then the government has no decision to make. They main reason the government has 'tough choices' is because it has chosen to take that decisions itself, putting its own, single choice in place of the many different choices that individuals would have made for themselves.
If there is a role for the state it is in publicising and properly regulating charities, so the public are well informed to be able to make their own choices about what to support.
If, given suitable publicity, a charity does not receive the support it requires then it deserves to fail.
RNLI (http://www.rnli.org.uk/) shows that state funding is not needed even for major emergency services. No government spending cut will ever damage RNLI's ability to deliver its service - as long as people have some money that they can choose how to spend, they can support the services they choose to care for. Cutting tax (involuntary donations) gives people the dignity, responsiblity and reward of making their own voluntary donations as they see fit.
Problems would no longer 'someone elses to deal with' or 'the governments responsiblity' - peoples choices will matter and make a difference, people will matter more - both to themselves and others.