Members of Parliament should always behave with probity and integrity when making claims on public resources. MPs should be held, and regard themselves as, personally responsible and accountable for expenses incurred, and claims made, and for adherence to these principles as well as to the rules.
This is one of the 'rules' that MPs should obey and respect willingfully, and should follow it unconciously. However, we know that some MPs don't follow this and don't hold themselves accountable for claims made; and I have long believed that the promises politicians make to gain election votes should be as valid as a verbal contract. The populace invest their vote into these promises, granted, the reality of politics, economics and the government are such that some promises may be unattainable. However, particularly with a politics party system where it may safely be assumed that representative candidates have access to advisors with some sort of expertise. They should be well-informed or advised about possibility vs. probability before opening their mouths to make promises. This is because they show know if their promises are beyond their possibilites and power and if they're attainable.
How should the voters know what they're voting for as well as who they are voting for? This aslo means that the populace don't know if the promises they are hoping for will be upheld or if their vote would go towards the cause they are voting for. For example, the brexit the majority voted for what happened, however, the £350 million the NHS was said to get still hasn't been achieved, and will most likely not happen. Imagine the thoughts of the people who wanted more jobs, the NHS to be more finicially stable, but they got their vote 'stolen' away by unkept words and promises. That most likely won't be achieved; and for this, they should be held resposible, for promising the possible, but never delivering the finality of it.