HONG KONG (Reuters) - Hong Kong's leader has signaled he might ask Beijing to use a rarely invoked power to interpret the city's Basic Law mini-constitution to end a political crisis over a fledgling independence movement.

Any such move will spark fears for Hong Kong's autonomy and vaunted legal system, officials, judges and lawyers say privately.

Chief Executive Leung Chun-ying's remarks on Tuesday come ahead of a Hong Kong government-requested legal hearing that could effectively bar two recently elected pro-independence lawmakers from the legislature of the global financial hub.

Some local officials and judges have grown privately fearful that the emergence of independence issues could see Beijing force tough new laws on the city, or interpret the Basic Law to explicitly curb pro-independence legislators.

The city's rule of law and freedom of speech is jealously guarded by many in the former British colony after it returned to Chinese rule in 1997 under the principle of "one country, two systems", allowing it wide-ranging freedoms.

Speaking ahead of a weekly executive meeting on Tuesday, Leung went further than other officials in raising the prospect that his government could request Beijing to interpret the Basic Law.

"We hope to do our utmost to resolve it within Hong Kong, but we cannot rule out this possibility," Leung told local media.

Justice Secretary Rimsky Yuen has said previously said that there was no need for an interpretation at this point, and said later on Tuesday he still "hopes" the issue can be handled locally.

The government has asked the courts to review a decision by the legislature's president allowing pro-independence lawmakers Yau Wai-ching, 25, and Baggio Leung, 30, to re-take their oaths of office. The hearing starts on Thursday.

The pair, who represent a new breed of more radical activists moving into the political mainstream, had their swearing-in oaths invalidated last month over language and a banner that was deemed derogatory to China.

"Apart from the case in court ... there is a high possibility that other things might be triggered by their oaths and their words and actions afterwards," the chief executive said, explaining why he had postponed a trip to Beijing.

In response, the two lawmakers said in a joint statement that if an interpretation was to take place, it would mean the Chinese Communist Party ruled over Hong Kong directly.

Pressure has built in recent weeks from local Beijing loyalists and the president Legislative Council last week delayed their swearing-in until the High Court rules.

Beijing's chief representative in Hong Kong did not mention the possibility of an interpretation in a speech later on Tuesday but said the lawmakers "seriously violated" China's constitution, the Basic Law and the relevant Hong Kong laws.

"Any speech and action promoting Hong Kong independence should be punished according to the law. There is no reason to be lenient," said the head of the Liaison Office, Zhang Xiaoming.

Once taboo, calls for self-determination and independence have risen since the 79 day struggle in late 2014 when tens of thousands took to the streets for 79 days of protests against reforms that failed to deliver full democracy for leadership.

(Reporting By Greg Torode. Additional reporting by Venus Wu.; Editing by Michael Perry and Alison Williams)