Jeremy Corbyn is expected to attack the Government for failing to act on corruption and tax avoidance in today’s launch of the official campaign period preceding May elections.

This follows public outrage from the revelations contained in the “Panama Papers”, detailing the widespread use of offshore financial services to avoid paying tax in domestic countries.

The Labour Leader will claim the party will campaign against the UK having “one rule for the rich and another one for everyone else”, saying the Papers underscore how the Government has failed to stand up for communities and instead protect the super-rich.

He is expected to renew his long-running attack on tax avoidance saying they are “sucking revenues” out of the country, attacking the government for cutting public services in the face of the richest keeping their wealth abroad.

“The publication of the Panama Papers this week drives home what more and more people feel, that there is one rule for the rich and another for everyone else. It is time to get tough on tax havens. Britain has a huge responsibility. Many of those tax havens are British overseas territories or Crown Dependencies.

“As the leaked documents show, tax havens have become honey pots of international corruption, tax avoidance and evasion. They are sucking tax revenues out of our own country and many others fuelling inequality and short-changing our public services and our people.

“The Government needs to stop pussyfooting around on tax dodging. There cannot be one set of tax rules for the wealthy elite and another for the rest of us. This unfairness and abuse must stop. No more lip service. The richest must pay their way.

“It is unacceptable that while councils’ budgets are cut and the services on which people rely are being cut back, the super-rich elite dodge their taxes and flout the rules.”

John McDonnell has made tax avoidance a priority for Labour following the Conservative’s “sweetheart” tax deal with Google, publishing his tax return and demanding more transparency from Government.

The elections are widely perceived as the first major test of Corbyn’s leadership of the party. A poor result will likely lead to discontent from Labour MPs and the membership, threatening his position.

Members of Scottish Parliament, the Welsh Assembly, local authorities, police and crime commissioners and the London Mayor are being elected.

Opinion is divided on Labour’s chances at the ballot box. A poll released yesterday shows London Mayoral candidate Sadiq Khan with a 8-point lead of Conservative rival Zac Goldsmith.

However, recent polling of Scottish Labour’s chances show them losing 12 MSPs at Holyrood house, while Welsh Labour stand to lose their majority with significant gains for UKIP.

Nationally, Labour has trailed the Conservatives in polls since last year’s General Election, though has recently won a one-point lead following George Osborne’s shambolic Budget.