Former UK Foreign Secretary Jack Straw says Saudi Arabia’s foreign policy pursued by Crown Prince Mohammed bin Salman "could end up as a threat in Lebanon unless wiser council prevails.”

Speaking at a conference hosted by London-based media monitoring group Middle East Monitor on Saturday, Straw described the Saudi policies extremely risky for the region and warned against a military intervention in Lebanon.

Lebanon is embroiled in a political crisis with Saudi Arabia over Prime Minister Saad Hariri's surprise resignation in Riyadh and his failure to return to Beirut amid speculation that the premier and his family are being held hostage by Saudi authorities.

Saudi Arabia has called on its citizens to leave Lebanon and described Hezbollah's presence in government as an "act of war". The Lebanese resistance movement, for its part, has accused Riyadh of having "declared war" on Beirut.

Straw said there has to be an acceptance of Hezbollah’s role in Lebanese politics. “Hezbollah as a political force is a reality in the Lebanon,” the Middle East Eye quoted him as saying.

The former top diplomat said that it was important to push for negotiations when dealing with international crises, citing the boycott of Hamas by foreign governments as a failure in this respect.

“I am unhappy about our boycotting of Hamas. I talked off the record to some journalists in Riyadh in early 2006 and said we ought to be talking to Hamas," he said, adding "some people say I was removed from the post of foreign secretary” because of these comments.

Straw was sacked by former British Prime Minister Tony Blair in 2006 amid claims that he had upset former US President George W. Bush with his views on the Middle East.

Lebanese women wave Hezbollah flags while holding a picture of the movement's chief Hassan Nasrallah in Mashghara in the western Bekaa Valley on May 25, 2013 during a ceremony marking the 13th anniversary of Israel's military withdrawal from Lebanon.

New Saudi rulers

Straw said the former generation of the Saudi rulers which he dealt with during his period in office between 2001 and 2006 were much more cautious "when it came to the social environment in Saudi Arabia."

Riyadh's diplomatic crisis with Beirut comes in the midst of unprecedented jailing of hundreds of princes and businessmen and seizure of their assets in Saudi Arabia, seen as an attempt by the crown prince to assert his rule over the kingdom.

Madawi al-Rasheed, a Saudi opposition campaigner and visiting professor at the Middle East Center at London School of Economics, told the MEMO conference on Saturday that there were few left in Saudi Arabia who could oppose the crown prince's power grab.

"Nobody in the history of Saudi Arabia has amassed so much power and control over institutions like MbS (Mohammed bin Salman) has been able to do,” she told the session.

Saudi authorities have characterized the arrests as part of an anti-corruption campaign which has hit a chord with young Saudis but Rasheed said all that was "a great PR initiative."

"It's almost like a phantasmagoria, an illusion that everyone is buying into," she said, pointing out that the kingdom had some of the world's highest youth unemployment, "almost equivalent to Gaza, which is under occupation."

Crown Prince Mohammed is the shoo-in for the throne and his father, King Salman, is believed to abdicate soon.

As the heir apparent, he has adopted a confrontational foreign policy and become a driving force behind a military intervention which has plunged Yemen into a humanitarian crisis.

On Saturday, Straw said, “The key cause of the humanitarian crisis in Yemen is the blockade and the bombings by the Saudis and the UAE.”

He warned that “as long as Saudi thinks that major Western countries are going to support whatever they do, regardless, they’re going to keep doing what they’re doing."