Jeremy Corbyn has declared Labour is "staking out the new centre ground" in British politics and he is leading a "government in waiting".
In his new year's message, the Labour leader said the prospect of a "new Britain" was "closer than ever before".
After a dramatic 2017 which saw Labour defy predictions of a landslide defeat at a general election which instead resulted in Theresa May losing her Commons majority, Mr Corbyn vowed to use 2018 to help people "fulfil their hopes".
"Ours is a fantastic country full of wonderful, caring and talented people with the hope of a great future ahead of us, where we all share in the wealth we create," he said.
"But we are being held back by a self-serving elite who look after themselves and their friends, and a failed system which delivers staggering wealth at the top while more and more people struggle to simply make ends meet."
The 2017 general election showed "the establishment's secret is out: they're not as strong as they appear" and have "no idea how to fix their broken system or upgrade our stagnant economy".
In 2018 "Labour's mission is to give our people support and security and use their talents, unleash their creativity and fulfil their hopes".
Mr Corbyn, a veteran of Labour's left wing, insisted that the party he leads now represents a new centre ground in British politics.
"The old political consensus is finished," he said. "We are staking out the new centre ground in British politics, backing the things which most people want but are blocked by vested interests.
"We are a government in waiting, while the Conservatives are weak and divided and stuck in an outdated rut with no new ideas. The hope of a new Britain, run in the interests of the many, not the few, is closer than ever before. Together we can, and we will, deliver it."