The charity wants to recruit 50,000 people to join a ‘core team' of 20 walkers, who will take in more than 60 UK towns and cities on their 1,000-mile trek.
The overall aim of the march is to highlight the devastating impact of global warming on the populations of developing countries.
Christian Aid intends to use the publicity generated by the walk to lobby the Government to reduce the UK's carbon emissions by five per cent year-on-year.
Concerts are also planned in various cities to mark the arrival of the walkers.
The core team, yet to be announced, is expected to be a mixture of people from the UK and developing nations such as El Salvador and Tajikistan, where Christian Aid is engaged in climate change projects.
The march, starting in mid-July, will last 11 weeks.