Sadly, news that Greece is last among European Union countries on Transparency International's Corruption Perceptions Index is not surprising. The emerging tax evasion cases, the scandal of people falsely declaring themselves blind on the island of Zakynthos, and the drama over the leaking of the "Lagarde list" of tax evaders have hit the headlines around the world.

Not only is Greece the lowest ranked EU country in an index that measures experts' perceptions of public sector corruption: in 94th place, it ranks a massive 19 places behind the next EU member state, Bulgaria.

Greece is not alone in Europe in needing to wake up to corruption. Portugal and Spain share the same weak oversight of public spending, with auditors too weak or lacking independence from government. Many European countries do not oblige political parties to disclose donations from companies, are lax in regulating the way businesses lobby politicians and officials, or lack scrutiny over governments tendering of contracts to businesses.

Greece's low rank tells a story. It illustrates the "crisis of values" that is driving the economic crisis, according to a report on corruption risks in Greek institutions published earlier this year.

The lack of accountable leadership – together with the deficit of transparency in the management of public finances and public spending – left us exposed to risk-taking and exploding debt, which brought us to today's crisis.

To a large extent, Greece's economic future depends not only on bailouts, but on how well it fights corruption. Bribery, tax evasion and a host of other mistakes have contributed to the present crisis Greece faces, and threaten to block any economic route the country takes in the future – default, bailout, austerity or stimulus.

When Transparency International assesses Greece's institutions, we see flaws, but also positives that show corruption can be tackled. Greece's ombudsman, for example, is well equipped to combat corruption thanks to a clear mandate enshrined in law and a well-trained staff.

Corruption can be tackled, but the reforms must run deep.

Last week in Athens, Transparency International Greece and the European commission presented a plan for tackling corruption in the country. Looking at today's Corruption Perceptions Index, it becomes imperative that the anti-corruption initiatives presented at the conference are implemented promptly.

A good start would be greater coordination of Greek anti-corruption agencies under a national co-ordinator. Our study earlier this year on corruption in Greece has found that despite the extensive cases of corruption reported, only about 2% of civil servants are subject to disciplinary procedures. .

If the anti-corruption initiative is to have any chance of success, the government should send a strong message by having the national co-ordinator report to the prime minister. Only when the prime minister champions the cause of transparency will Greece start to get rid of corruption.

The creation of a strong anti-corruption body proved a turning point in Hong Kong in the 1970s, helping it emerge from the control of organised crime to its present reputation for integrity – it's now ranked 14th in Transparency International's Corruption Perceptions Index. It has prosecuted more than 12,000 public officials. Greece, sitting 80 places further down that ranking, needs to follow that example and allow no impunity for corruption.

We live in an era where there is a rising tide of public demand for leaders to be more accountable for their actions. Time and again we are seeing leaders who fail to respond to that demand swept from power.

It is time for leaders to step up, lead by example, and cultivate a culture of integrity.