Jeremy Corbyn has appealed to people who do not think of Labour as their natural political home to "think again" if they value public services.
In a Sunday newspaper article, he said countless numbers had been let down in the last six years by the "devastation" of public services.
He also launched a fresh attack on Southern Railway, saying the poor level of service in recent months proved that the railway industry should be renationalised.
Writing in The Sunday Telegraph, he said: "Over the last six years you've been deceived on a scale not seen since Bernie Madoff's infamous Ponzi scheme.
"Time and again you've been told that to build a strong economy we had to tighten our belts and cut public funding.
"Today we have the utterly self-defeating reality of rapidly declining public services while our debt is going up.
"Waiting times are up, critically cancer waiting times are up. In some parts of the country a GP appointment is as rare as hen's teeth.
"We are spending over £2 billion a year on agency and contract staff. If you want to truly understand the almost Kafkaesque state of the NHS in Tory Britain today then look at Kings College Hospital in London.
"Hugely in debt, they are paying a freelance contractor the equivalent of £715,000 per year to be their 'turnaround' director."
Mr Corbyn criticised the Government's handling of Southern Railway, which faces a five-day strike from Monday after weeks of delays and cancellations.
Before the company cut over 300 services last month because of staff shortages, passengers were facing a "woefully inadequate" service with delays, overcrowding, cancellations, late running trains as the norm, he said.
"Yet instead of recognising the plight of millions of passengers and telling Southern Rail where to get off, the Government continues to support them with our money.
"The fact is, the economic decisions this Government are making are out of choice not circumstances. The choice for you and millions like you is what type of country you want.
"Even if you don't think of Labour as your natural political home, if you value your NHS, care for the elderly, an education system for all and a public transport system that works for its passengers, then it may be time to think again."
In another interview, Mr Corbyn restated his support for an elected Upper House of Parliament, denouncing David Cameron's controversial resignation honours list as "another nail in the coffin" of the House of Lords.
Mr Cameron nominated 13 new life peers on Thursday, including Conservative donors and Downing Street staff, while Mr Corbyn also attracted criticism by nominating civil liberties campaigner Shami Chakrabarti shortly after she completed a report on allegations of anti-Semitism in the Labour Party.
The Labour leader told The Sunday Mirror: "I want the House of Lords abolished and replaced by an elected upper chamber."
Describing the 800-member second chamber as "far too big", he added: "Cameron's cronyism has been quite appalling.
"Honours appear to be linked to donations to political parties and personal service to members of his family.
"I would also say that serving politicians should not be given honours because it's honour enough to be elected to public office."
Speaking to the Huffington Post UK, Mr Corbyn rejected shadow chancellor John McDonnell's suggestion that it was "inevitable" both of them would step down if Labour lost the general election.
"Look, nothing is inevitable," said the Labour leader. "And let's not start predicting the results of the next general election, which may be four years away."
Asked if he would step down if poll ratings do not improve and Labour loses council seats, Mr Corbyn said: "The party members control what happens. They will decide, one way or another."
Responding to criticisms of his leadership style, Mr Corbyn said: "The idea of the be-all, know-all, see-all, do-all, control-all leader is something that is not very happy or healthy in a democracy. It is about communities and people."