Image copyright AFP Image caption China's central government is seeking a stronger role in Hong Kong

China has warned foreign countries against "meddling" in Hong Kong's politics ahead of a crucial announcement on the territory's election process.

Chinese state media said using Hong Kong as a "bridgehead to subvert the mainland" would not be tolerated.

China is expected to limit elections to a selection of pro-Beijing candidates.

Pro-democracy activists in Hong Kong have threatened mass disobedience if elections are not opened up.

They say they will stage a mass sit-in in the city's financial district if an acceptable agreement is not reached.

Outside forces

An article in the Chinese state-run People's Daily on Saturday said that some in Hong Kong were "colluding" with outside forces.

"Not only are they undermining Hong Kong's stability and development, but they're also attempting to turn Hong Kong into a bridgehead for subverting and infiltrating the Chinese mainland", the article said (in Chinese).

"This can absolutely not be permitted" it said, quoting an unnamed foreign ministry official.

The article did not identify which outside forces were being accused of involvement, although many countries in the west have called for more open government in the former British territory.

The Standing Committee of China's National People's Congress has been meeting to determine election regulations in Hong Kong, and will announce their decision on Sunday.

Image copyright AP Image caption On 1 July tens of thousands marched against candidate restrictions in the territory

Image copyright Reuters Image caption Pro-democracy activists held an unofficial referendum on the election proposals in June

Image copyright AFP Image caption Tens of thousands also joined a pro-Beijing rally on 17 August in Hong Kong

Correspondents say it is highly likely that China will require candidates for the position of chief executive to obtain support from a nominating committee.

Most expect that committee to be made up of pro-Beijing businessmen and individuals, thereby giving mainland authorities an effective veto over candidates.

The issue is the subject of huge debate in Hong Kong, a former British colony now governed by China under the principle of "one country, two systems".

In June, almost 800,000 people cast ballots in an informal referendum organised by Occupy Central on how the chief executive should be chosen.

This was followed by large-scale rallies held by both sides.

Hong Kong has retained wide legal and economic powers since being handed back to China in 1997.

But some activists are worried that China's central government is seeking to exert greater political control over the territory.