Hello, I'm Justin Green with the BBC news.

The highest legal authority in Greece is due to hear an appeal contesting the legitimacy of Sunday’s referendum on the international bailout. Lawyers have been debating whether the vote violates constitutional rules. Greece's Finance Minister Yanis Varoufakis said the referendum will allow the country to choose between a bad imposed agreement and a viable deal with spare economic recovery. From Athens, Chris Morris.

"The Prime Minister Alexis Tsipras says the vote for or against austerity and rejection of the terms offered by his country’s creditors will strengthen his hand in future negotiations. But the opposition, backed up by some of the warnings from elsewhere in Europe, says this is in effect a vote on whether to stay in the Euro Zone. The IMF has also warned the rest of the Euro Zone that in the long term, the Greece’s debt is unsustainable and they will need a comprehensive debt relief. Politically, that is an unpalatable thought."

China has announced that it is investigating suspected manipulation of its stock market after they suffered their worst collapse in years. The Chinese securities regulator is also reported to a suspended 19 accounts that were short selling the market and expecting the stock would fall. Martin P is in Beijing.

"Until a few weeks ago, the Chinese markets were among the best performers in the world, the Shanghai Exchange more than doubled its value in 12 months. But in recent days, China’s markets have suffered huge losses, wiping trillions of dollars of share value. Now China’s securities regulator says it’s investigating whether parties are mis-selling financial products. Analysts say there is now growing panic in the markets, as investors try to off load their shares to stand their losses."

Ceremonies will be held in Tunisia and Britain to remember the 38 tourists shot dead by an Islamist gunman last Friday. A minute's silence will be observed in both countries while flags will fly at half mast over Buckingham Palace and British government ministries. Tunisian officials said they've uncovered the network behind the attack and are holding eight people suspected of direct links with the gunman who was shot dead.

Malaysia has told the UN Security Council it wants to set up an international criminal tribunal to prosecute those suspected of shooting down a Malaysian Airline's flight over Ukraine last July. Ben L reports.

"In the wake of the crash, the Security Council adopted a resolution promising to bring the perpetrators to justice. Two thirds of crashed victims were from the Netherlands and the Dutch authorities have taken a lead in the investigating. Their final report won't be published until October. But Russian officials have criticized the draft of the document, saying it presents more questions than answers. Moscow described the proposal for a tribunal as 'premature'."

World news form the BBC.

South Korea is to increase public spending to counter the slowdown on its economy. The government has decided to increase spending by more than ten billion dollars to counter the sluggish spending by consumers in businesses. As our Korea correspondent Steve E reports, this is a different approach from that currently being adopted in Europe.

"The Chinese economy is the main cause of South Korea’s slowdown, but the outbreak of MERS also raises a fear for the future. Accordingly, some of the extra spending is targetted at hospitals and clinics, which failed to cope when the illness first appeared. But the detail doesn’t seem as significant as its big picture. South Korea is rejecting the economies of Europe."

An unmanned Russian rocket has blasted off from the Baikonur xx in Kazakhstan on a supply run to the International Space Station. Flight controllers will relive the initial lift-off without any mishap. Two previous supply rockets were lost in accidents. Last Sunday, a rocket has exploded shortly after launch.

Spiders have been found to travel across water like ships using their legs as sails and silk as an anchor. Researchers of Nottingham University in England say spiders adopt postures that allow them to use wind currents to move. Tests carried out on trace of water show that many species put their legs in the air to catch the wind. Spiders were already known to use their silk in so-called "balloons" to enable them to fly.

A Chinese company is planning to introduce policies that will require its employees to seek an approval to start a family. The screen short of a document has been published, sparking a wave of complaints on social and official media. It outlined how only married women who worked at the company, the Finance House in Henan Province, can apply for a place on its birth planning schedule. Anyone else who gets a pregnant will be fined and be passed over for promotion.

BBC news.