Before he was British prime minister, David Cameron railed against "the far too cosy relationship between politics, business and money", and called it "the next scandal waiting to happen".

The waiting's over. Last month, the treasurer of Cameron's Conservative party, Peter Cruddas, was forced to resign after a newspaper filmed him offering an intimate dinner with the PM in return for a donation of £250,000. After initially trying to dismiss this as a non-story, a one-off gaffe, Cameron was forced to release details of everyone he's had dinner with.

Cash for access

Exercising influence on political decisions is big business. In the UK, around 4,000 people earn their living through professional lobbying; the industry is worth £2bn. In a system of revolving doors, political decision-makers often move into well-paid lobbying jobs once their terms are up, muddying transparency and impartiality.

This is not just a matter of who has dinner with whom, or who gets a job. From the assault on the NHS by the private healthcare lobby, to big business lobbying for the internet gag agreement Acta, unregulated access for lobbyists is undermining democracy.

Something, but not enough

Embarrassed by the Sunday newspaper exposé of Peter Cruddas, the government has finally got around to publishing a long-promised proposal for a mandatory register of lobbyists. In theory, the register should open up to scrutiny the names of all those who meet with ministers and civil servants. But in its current form, it has some big flaws – not least that won’t cover the most powerful lobbyists, including those employed “in house” by corporations. (Tesco – Britain's biggest supermarket chain – employs several in-house lobbyists).

Unless the proposal is strengthened, corporate access to political decision-makers will continue to be an unregulated free-for-all. Other countries, such as the United States, already have strict rules for lobbyists, including compulsory registration for anyone acting on behalf of foreign countries or for political gain. Instead of lagging behind, Britain could set international best practice with a robust register.

Take action:Sign Unlock Democracy's petition to Britain's constitutional reform minister Mark Harper, demanding an effective, wide-ranging and transparent register of lobbyists.