Caroline Lucas MP, leader of the Green Party, tonight wished outgoing prime minister Gordon Brown well - and once again drew attention to the urgent need for electoral reform.
In a statement issued late this evening the newly-elected Green MP for Brighton Pavilion said:
"Tonight, Gordon Brown has laid down the burdens of the office of Prime Minister with good grace and I wish him well for the future. David Cameron now takes up those responsibilities and faces four challenges.
"First, bringing in comprehensive political reform, including letting the public choose how politicians are elected, that will help restore people's faith in politics. If the Lib Dems have failed to secure a genuine commitment on this, this is the biggest betrayal of the British electorate in a generation.
"Second, dealing with the crisis in our public finances while protecting those in the greatest need.
"Third, replacing rhetoric with real action on climate change.
"Fourthly, and finally, for Britain to become a force for good in the world, and to bring our military involvement in Afghanistan to an end.
"We do not underestimate the difficulties ahead. We will support where we can; and always provide a principled and progressive alternative."