A Volkswagen worker wearing a T-shirt reading ‘One team, one family’ at a company meeting at the Wolfsburg plant, yesterday. Photo: Reuters

Hans Dieter Poetsch’s first board meeting as chairman of Volkswagen today could turn out to be his most important, coming just hours before a deadline set by German regulators and testimony by the company's top US executive in Congress.

More than two weeks after the carmaker admitted to cheating US emissions tests, Poetsch will be appointed to the helm of the 20-person supervisory board at a specially convened meeting at the German company's headquarters in Wolfsburg.

Sources close to the company say this morning’s meeting is likely to last for hours, given the number and gravity of the issues to be discussed.

Europe’s largest carmaker is under huge pressure to find those responsible for installing software in diesel engines to rig emissions tests, to say how affected vehicles will be fixed and to what extent it may also have cheated in Europe.

The biggest business crisis in Volkswagen’s 78-year history has wiped more than a third off its share price, forced out its long-time chief executive and sent shockwaves through both the global car industry and the German establishment.

Yesterday,more than 20,000 workers gathered at the company’s sprawling Wolfsburg plant to hear CEO Matthias Mueller address them for the first time since he replaced Martin Winterkorn two weeks ago.

“We will overcome the crisis,” Mueller told staff, many of them wearing specially printed T-shirts with the slogan “one team, one family” to show their support for the company. Mueller warned all projects and investments would be put under review and there would be “massive cuts”.

We will overcome the crisis... one team, one family

But Volkswagen’s ability to recover could also depend on what happens on two key dates this week: Germany’s KBA watchdog has set a deadline for today for the company to submit a plan to make its cars compliant with emissions laws and the company’s top US executive is due to testify before a US congressional oversight panel tomorrow.

Since Volkswagen’s cheating was exposed on September 18, the carmaker has come under fire for a slow response.

While it admitted on September 22 that 11 million diesel vehicles worldwide were fitted with illegal software, it only provided customers with information about whether their cars and vans were affected on Friday.

Owners have been told their vehicles will have to be refitted but do not know if this will affect their fuel economy or performance – key issues that could determine the number of lawsuits and amount of damage to Volkswagen’s reputation.

Analysts and investors are also anxious to know whether Volkswagen cheated emissions tests in Europe too. Given eight million of the 11 million affected vehicles are in the EU, any cheating could have a bigger impact than the US in terms of fines and lawsuits.