Greens parliamentarian Frithjof Schmidt had asked “Why does the German government tolerate this extremely unusual – and in my opinion illegal – behaviour of a foreign head of state conducting politics on German soil?”
Thousands of protesters have been holding demonstrations in Bangkok over recent months calling for reform of the monarchy to curb the king’s powers and for the removal of Prime Minister Prayuth Chan-ocha, a former junta leader, and a new constitution and elections.
Schmidt also asked Maas whether Germany was prepared to discuss with the European Union freezing free trade talks with Thailand again “as long as the junta continues to block the path to democracy”.
The EU halted contact at all levels with Thailand after a 2014 coup but resumed trade talks after a general election last year that saw Prayuth, a general, reinstated as a civilian prime minister.
Maas said that halting negotiations was “an option” to exert pressure but it would be right to discuss with Thailand first.
Neither the Royal Palace in Bangkok nor the Thai government responded immediately to a request for comment.
Protesters challenging the palace and army-dominated establishment broke a long-standing taboo by demanding reform of the monarchy.
Vajiralongkorn, 68, has been on Thailand’s throne since 2016, but spends much of his time in Bavaria, where his 15-year-old son is at school.
Thai protesters have complained about the cost of the king’s stays in Europe as well as his absence from the kingdom.
The protesters seek to reduce his powers under the constitution, which specifically allows him to exercise powers when he is outside Thailand without appointing a regent.
Protesters also want to remove his direct control of a royal fortune valued in tens of billions of dollars and some units of the army. The Palace has made no comment on the protests.
Protesters in Thailand on Thursday said they would rally again next Wednesday and expected a big turnout to pressure the government to step down and press their calls for reform of the monarchy.