This Tuesday, King Carl XVI Gustaf opens Sweden's parliamentary year in the presence of representatives of all main political parties. While Swedish parties will soon continue politics as usual, many of their sister parties across Europe are experiencing existential threats stemming from a range of political insurgents. In just the last 18 months, political movements that defy traditional politics have turned party systems upside down from Germany to France, from Italy to Spain and from the UK to the US. Swedish parties should take heed.

Two weeks ago, France's popular Economy Minister Emmanuel Macron resigned to lead En Marche!, a new political movement that refuses to call itself a party. That same week, the young Alternative für Deutschland defeated the powerful CDU in regional elections. Meanwhile, in Britain, Jeremy Corbyn is tightening his grip on the Labour Party in defiance of the party establishment. So is Donald Trump, who won the Republican presidential candidate against his party's well, mostly with the help of Twitter.

Further south, in Spain, the two upstart political movements Ciudadanos and Podemos which grew out of street protests have ruptured the country's two-party system. And in Italy, the Five Star Movement just won the mayoral elections in Rome and Turin. The blog of its unofficial leader, comedian Beppe Grillo, is one of its main weapons. In the US, Bernie Sanders, while not making the presidential candidate nomination, has defied the traditional way of doing politics in the US, mobilizing grassroots voters both politically and financially.

What defines this motley crew of political movements, running from Europe's political left to the political right? All of them are loosely organized, defy traditional party structures and claim to have direct contact with a disgruntled electorate. They feed on a growing group of angry citizens, who distrust government over incomprehensible policies or high-level corruption. Many stem from protest movements and maintain close contact with those movements after their transition to politics. They infiltrate traditional party systems or existing parties and revolutionize them from within. Their leaders live, talk and often dress differently. And lastly, they rely on social media and other new technologies to connect to citizens in a more direct way.

To say that Swedes are happy with their party system or that Sweden is immune to such movements is naïve. In Sweden, as in Europe, citizens have in recent years moved to a new market space of active citizenship. Citizen discourse increasingly takes place not in party gatherings but in coffee bars, on streets and in social media. Political party relations with citizens have changed from predominantly vertical relations to more horizontal relations that reflect the way people work, interact and live in today's societies. If Swedish parties want to occupy this new market space, they need to innovate rapidly and the success factor has to do with trust. Trust in the parties and in the state.

Swedish voter turnout is admittedly among the highest in Europe. But the same goes for Germany and the UK, both of whom have seen a shakeup of their party systems. Moreover, what defines citizen support to political parties may not be voter turnout. For instance, only five percent of Swedish citizens are members of a political party, which is below the European average, and of those only 1.5 percent are politically active.

Despite a trend towards younger political party leaders (average age is now 42, down from 50 years ago), party membership suffers from 'geritatrization': political party membership is disproportionately represented by older age groups, with half of all party members being over the age of 65; among the plus-65 population, ten percent are members of a political party, while this is the case for only four percent of the under-25s.

Hence, the failure to politically mobilize the citizenry through traditional political parties, sparking political movements elsewhere, also exists here. Couple this with Sweden's high interest in innovation of any sort (a recent poll showed that Sweden has Europe's highest trust in social media's benefits to democracy) and you get fertile ground for the emergence of a political movement.

Established parties are, however, not doomed to extinction: several European parties, from the Conservatives in Norway to the UK's Green Party, have introduced new modes of citizen involvement, public outreach and citizen forums – and have grown substantially as a result. Most parties in France are today organizing open primaries, ahead of the 2017 presidential elections.

There are many ways in which Swedish parties can also strengthen or reconnect to citizens, but three lessons from the continent stand out: with a shrinking political party membership base, Sweden's select group of party members need to accept more influence from non-members when designing policies, recruiting candidates, or nominating leaders in order to have a relationship to their voters and supporters.

Secondly, Swedish parties are latecomers to new technologies. They should embrace technology to allow larger citizen involvement in policy making, internal voting or citizen outreach. And thirdly, parties should be absolutely transparent in their financing, which is an area where Sweden lags behind in Europe, as the Greco commission of the Council of Europe reported in January 2016.

At the opening of the parliamentary year, parties would do well to look around the rest of Europe, and reserve a moment of self-reflection in order to strengthen the trust between citizens and parties.

Written by Sam Van der Staak, senior programme officer at the International Institute for Democracy and Electoral Assistance and Jens Orback, the Secretary-General of the Olof Palme International Center and former Minister for Democracy, ahead of an Idea panel debate on the topic on Tuesday.