Bärbel Höhn stopped believing in coincidence long ago. The Green party politician says she rubbed her eyes when she first read of the large donation made by major BMW shareholders to the Christian Democratic Union, the governing party led by Chancellor Angela Merkel.

Less than three weeks after the general election, three members of the Quandt and Klatten families transferred some 690,000 euros ($930,000) to the CDU. As is legally required of any donation over 50,000 euros, the figure was published on the German parliament's website.

Cash for lax emissions limits?

The transaction was completely legal, but Höhn is outraged nevertheless, because it came just as Merkel's government was working to protect the interests of the German auto industry at the European Union.

Höhn thinks it's high time for reform

"It does have a bitter after-taste if a major donation of 690,000 euros comes from BMW at the same time as the chancellor is doing everything she can to block a really ambitious CO2 limit for cars," she said.

German Environment Minister Peter Altmaier - also of the CDU - prevented an agreement being reached at a summit with his EU counterparts in Luxembourg on Monday (14.10.2013). Instead of the stricter emissions regulations from 2020 that the EU Commission called for, the German government demanded more generous transitional limits, which principally benefit the limousines built by German auto giants BMW, Daimler and Audi.

Höhn suspects that the government's policy was bought - a charge the CDU denied in a written statement: "The donations were and are in no way connected to individual political decisions."

That bold declaration isn't enough for German anti-corruption organization Transparency International, whose chief Christian Humborg is calling for a sea-change in party donations law in Germany.

The Quandt and Klatten families hold a major stake in BMW

No more self-policing

All party donations are currently governed by a law last reformed in 2011, which decreed that the parties decided themselves how their state contributions would be measured and set their own limits on donations from companies and private individuals. That means that parties can legally accept donations of any size at all.

The CDU is of course not the only party that benefits from these lax rules. In 2013, the Social Democratic Party, the Christian Social Union (the CDU's Bavarian sister party), the Free Democratic Party, and - oddly - the Marxist–Leninist Party of Germany, all received individual donations of between 60,000 and 150,000 euros.

No wonder, then, that Humborg is not holding his breath waiting for the parties to instigate change. "The law says that if the parties do not manage to reform the rules themselves, the president must intervene," he says. For that reason, he wants President Joachim Gauck to convene a party financing commission that limits major donations, forces new transparency laws, and makes the monitoring system more independent.

Germany under pressure in Europe

An expert commission formed by the Council of Europe also criticized Germany's donations rules. The Strasbourg-based Group of States Against Corruption (GRECO) even instigated a special process against Germany last year, because its recommendations on party donations had not been implemented to its satisfaction.

GRECO had called on Germany to introduce measures to ensure greater transparency by June 31, 2012 - a demand that has so far been ignored by both governing and opposition parties. In fact, the ties between Germany's powerful auto lobby and the political elite only seem to have gotten stronger. Ex-Transport Minister Matthias Wissmann - also of the CDU - has been chief lobbyist for the German Automobile Industry Association (VDA) for several years, and Merkel's former Minister of State at the German Chancellery, Eckhart von Klaeden, now works for Daimler.

Gysi says the cosy relationship between business and politics must stop

Gregor Gysi, head of the socialist Die Linke party, has had enough of this cosy arrangement. He wants to put a stop to the traffic of donations and personnel between industry and politics. "It is unacceptable that the rich in this society, the companies, always bind the parties to them so that they pursue the policies they want," he said. For him, it is hardly surprising that politics has developed such a bad reputation in this climate.

Gysi is even calling for Germany to join the alliance of countries that has banned all party donations, but Christian Humborg from Transparency International favors a more moderate approach. "Our recommendation is not to abolish donations completely, because money will always find a way," he said. Instead, Humborg would like to see more transparency, with all donations over 2,000 euros disclosed, and individual donations limited to 50,000 euros per person or company. He has already won the Green party's Bärbel Höhn over to this plan - which some cynics say is not surprising, since the Greens have received just three large individual donations in the past few years.