[webmobdev]

It's a feature of a multi-party parliamentary democracy - when a candidate is a representative of a party standing for any elections, and wins it, it is assumed that people voted for the candidate partly because of the electoral promises and visions of the party. Thus, if a party has made a promise to the electorate to enact some major law, and issues a whip in Parliament that all its representatives should support its passage, then they are legally bound to do so. They can still choose to abstain or even vote against it. But then the party can take action against them. (Note that this is only applicable when a party issues a whip, which democratic ones do only for laws it considers important.)