Chinese leaders endorsed a sweeping overhaul of Hong Kong's electoral system yesterday, creating powers to vet anyone standing for public office and slashing the number of directly elected politicians. 

The new measures, which bypassed Hong Kong's legislature and were imposed directly by Beijing, are the latest move aimed at quashing the city's democracy movement after huge protests.

President Xi Jinping signed the new law after it was unanimously approved by China's top decision-making body.  One of the most dramatic changes is the introduction of a committee that will vet anyone hoping to enter Hong Kong politics for their patriotism.

The body will include background checks by Hong Kong's new national security apparatus and its decisions cannot be legally challenged.

When Hong Kongers are allowed to vote in limited local elections, they tend to do so overwhelmingly for pro-democracy candidates, something that has rattled authoritarian Beijing.

Under the new measures, Hong Kong's legislature will be expanded from 70 to 90 seats.  But only 20 of those seats will now be directly elected, down from 35. That brings direct representation down from half to less than a quarter of seats. 

The majority -- 40 seats -- will be chosen by a reliably pro-Beijing committee. The remaining 30 will be chosen by "functional constituencies" -- bodies representing certain industries and special interest groups that have also been historically loyal to Beijing.