Germany’s education authorities are locked in a fierce battle over whether the country’s 16 states should be able to determine when they go on holiday.

Currently the states of Bavaria and Baden-Württemberg are permanently hogging what most believe to be the best school holiday summer slots – between the end of July and the start of September. The other states are locked into a strict rotation system running from June to September.

The system was introduced decades ago to ensure that the country’s infrastructure did not grind to a halt as it might if everyone decided to hit the autobahns, railways and airports at once. The rotation system is also meant to ensure a spread of holidaymakers across the season at hotels and holiday resorts, so that the economic benefit of the Sommerferien-Korridor – or summer holiday corridor – is maximised.

At a recent meeting of all the country’s education ministers, Bavaria and Baden-Württemberg were asked to show a little flexibility. But the prosperous southern states – particularly Bavaria, which has always prided itself in feeling like a separate nation within a nation – have delivered a firm nein to renegotiating the most precious time in most Germans’ calendars.

In response, other states have threatened to boycott the agreement whereby every state endures the inconveniences of the rotation system except Bavaria and Baden-Württemberg – which were originally allowed the fixed time so that children could help with farm work.

Hamburg has accused the states of egotism and said it will lead the way in deciding in future on its own summer break dates. It is urging other states to follow. Lower Saxony, North Rhine-Westphalia and Berlin have said they are prepared to do the same.

Under the rotating system, the summer holidays are set out for the next five years. The period between 2024 and 2030 has been the subject of tense negotiations between the states since October.

Berlin’s mayor, Michael Müller, has gone so far as to suggest that German federalism, often seen as a model for harmony and cooperation between states, and on which the European Union is roughly modelled, is under threat.

He cited the two southern states’ go-it-alone approach, not just on holidays but also nationwide standards for school marking systems and leaving certificates. Müller told the public broadcaster Deutschlandfunk that their attitude amounted to “repeated attacks on federalism”’ and reflected nothing of the “give and take” that such a system required to function. He has suggested a smaller corridor between July and September.

But the economic interests of the tourism industry to keep the corridor as long as possible are huge. In recent years it was between 90 and 95 days long. Shortening the corridor by just a single day has been estimated to lead to losses to the tourism industry of €120m (£102m).

A widely perceived smugness on the part of Bavarians on account of their going on holiday long after Berliners have returned from theirs triggers feelings of resentment and often envy in the rest of the population.

Among some Bavarians there is support for being more flexible so that families are able to enjoy holidaying in earlier, off-peak times, for example in neighbouring France or the UK or so that they can visit Scandinavia in June to enjoy the longest days of the year.