The US has been branded a “flawed democracy” thanks to crumbling confidence in its government and institutions.

Experts behind the Economist Intelligence Unit's annual Democracy Index rank the governance of countries worldwide, but have this morning cut the status of the American system for 2016.

Previously a part of the top level “full” democracy group, the US joins 56 other “flawed” states, including 17 EU members, as well as countries like Japan and South Korea.

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Joan Hoey, editor of the report, said the US had been downgraded because the EIU's data showed a consistent erosion of trust in the American government and elected officials in 2016.

“This is not a consequence of Donald Trump. On the contrary, the election of Mr Trump as US president was in large part a consequence of the longstanding problems of democracy in the US,” Hoey said.

The EIU also noted that these problems are not isolated to the US, with political elites also facing popular challenge in both the UK and Western Europe.

"The backlash was the culmination of a longstanding trend of deterioration in the quality of democracy in the US and Europe, which is manifested in declining trust, falling popular participation and the erosion of civil liberties,” Hoey said.

Where does the UK rank? The top 25 countries

Status Rank Overall score Full democracy 1 Norway 9.93 2 Iceland 9.50 3 Sweden 9.39 4 New Zealand 9.26 5 Denmark 9.20 6 Canada 9.15 6 Ireland 9.15 8 Switzerland 9.09 9 Finland 9.01 10 Australia 9.03 11 Luxembourg 8.81 12 Netherlands 8.80 13 Germany 8.63 14 Austria 8.41 15 Malta 8.39 16 United Kingdom 8.36 17 Spain 8.30 18 Mauritius 8.28 19 Uruguay 8.17 Flawed democracy 20 Japan 7.99 21 USA 7.98 21 Italy 7.98 23 Cabo Verde 7.94 24 France 7.92 24 South Korea 7.92

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The “flawed” definition indicates that elections are free and fair, and that basic civil liberties are respected.

However, it also identifies “significant” weakness in aspects of democracy, including problems in governance, an underdeveloped political culture and low levels of political participation.

Experts rated states across 60 different factors grouped into five categories – Electoral process and pluralism, functioning of government, political participation, political culture and civil liberties.

Of the 91 countries rated below “flawed” in the index, 40 are “hybrid regimes”, while 51 are outright “authoritarian”.

The UK remains in the “full” democracy group, indicating only “limited” problems. Norway tops the global rankings, while North Korea is bottom.