Germany’s most prominent climate activist, Luisa Neubauer from Fridays for Future, was offered a seat on the board of Siemens Energy by Siemens chief executive Joe Kaeser, but declined.

Siemens Energy is bundling the conglomerate’s gas and power activities, and will also own 59% in wind turbine manufacturer Siemens Gamesa. Siemens plans to spin off the energy unit at the stock exchange later this year, but will remain its anchor shareholder.

In what seems a publicity stunt that backfired, Kaeser had invited Neubauer to discuss climate issues, among them the participation of Siemens in the construction of the Carmichael coal mine project in Australia, which is slated to be one of the largest in the world.

Although Siemens is only a minor player in the project – the German conglomerate has an €18m ($20m) contract to provide the signal technology for a railway to export the coal from the mine to the coast – it has met mounting protests in Germany and is held responsible for a massive future rise in CO2 emissions. Many of the more than 7,000 tweets on the issue this morning contained the hashtag ‘boycottSiemens.’

Indian mining firm Adani, which is constructing the project, plans to ship most of the coal from Carmichael to India, where it will be burnt in coal power plants.

Neubauer in a tweet said she turned down Kaesers offer as she needs time to concentrate on her climate activism, but suggested that a member of Scientists for Future should assume the post instead of her, which Kaeser declined.

“With the position, I would be bound to the interests of the company and couldn’t comment any longer indepently on Siemens. That cannot be reconciled with my role as climate activist,” Neubauer is quoted as saying on the Spiegel website.

Kaeser after the meeting with Neubauer said he needs to contemplate until Monday about his company’s participation in the Carmichael project, but following an extraordinary board meeting said: “We need to fulfil our contractual obligations.”

The decision to follow through with the plans for Adani’s project increased protests against Siemens. Fridays for Future called for demonstrations this Monday, and has already confirmed 11 school strikes in front of Siemens offices.

Kaeser in a tweet said Siemens will “establish an effective Sustainability Board to better manage environmental care in the future.”

In an interview with Spiegel online, he also said that he told Neubauer that he supports many of Fridays for Future’s demands, but that the contract with Adani was already signed and cancelling it would endanger the company’s reputation for reliability.

Neubauer is the best known climate activist in Germany, and receives almost as much media attention in the country as Greta Thunberg. Fridays for Future has become a growing factor in German politics and is putting pressure on the government and large corporations alike.