Chancellor George Osborne and former opposite number Ed Balls are on the list to attend the famously secretive Bilderberg conference in Austria.
Guests at the traditional gathering of influential figures include Dutch Prime Minister Mark Rutte, Google executive chairman Eric Schmidt, and Nato secretary general Jens Stoltenberg.
The contents of their discussions are never released.
This year's agenda includes the UK, terrorism and the US elections.
Artificial intelligence, cyber security, Greece, Russia and 'European Strategy' will also be discussed.
The event, first held at the Hotel De Bilderberg in the Netherlands in 1954, describes itself as an "annual conference designed to foster dialogue between Europe and North America".
This year's is being attended by 133 people and lasts for three days.
Critics claim it is a front for a shadow world government, and the events often attract protesters.
In 2013, Mr Balls - who lost his seat in last months' general election - said he did not "really quite see what the fuss is all about".
The organisers say the secret nature of the discussions allows participants to "take time to listen, reflect and gather insights".
"There is no desired outcome, no minutes are taken and no report is written.
"Furthermore, no resolutions are proposed, no votes are taken, and no policy statements are issued," they say.