Helicopters will be hovering over a Watford hotel while armed police patrol the grounds today as a who's who of the most powerful politicians on the planet convene in the town for a two-day world summit.

Prime Minister Gordon Brown will host 15 of the world's leaders at the progressive governance conference, to be held at The Grove.

Among the illustrious guests attending the summit are Australian Prime Minister, Kevin Rudd, South African President, Thabo Mbeki and Chilean premier Michelle Bachelet.

The Prime Minister of New Zealand, Helen Clark and the President of Liberia, Ellen Johnson-Sirleaf are also attending the conference on globalisation.

Other guests are expected to include the head of the IMF, director of the World Trade Organisation and the head of the United Nations Development Programme.

Both The Grove and Policy Network, the international think-tank organising today's conference, have kept details of the summit under wraps until the last minute.

However, members of the resort's health spa, Sequoia, have been warned in advance that they may have their handbags or gym bags searched before they enter the hotel.

They have also been told they cannot bring a guest into the spa today or tomorrow.