On a whistle-stop visit to the east coast, the Labour leader visited a hospital which has been affected by a cyber attack.
Jeremy Corbyn met activists outside the James Paget University Hospital in Gorleston to talk about the widespread virus which knocked out NHS computer systems across the country.
His team cancelled a planned visit to the Palace Bingo in Great Yarmouth but instead diverted to the hospital so the Labour leader could address the issue, which has seen operations cancelled at the hospital over the weekend.
MORE: All weekend appointments cancelled at James Paget Hospital in GorlestonMr Corbyn said what was happening across the country was terrible.
He added: 'People are being held to ransom by what you could only call 21st century highway robbery. It's up to any of us who hold public office to protect people against this. 'It turns out that the contract to continue protecting the NHS system was not renewed by the government two years ago. So there has been no protection for two years.
'We also have the plethora of contracts in NHS hospitals all over the country. It seems to me what we don't need is a break up of our NHS. What we need is the unity of our NHS.'
A crowd of supporters awaited Mr Corbyn and staff from the hospital came out to speak to him.
The Labour candidate for Great Yarmouth Mike Smith Clare introduced his party's leader to the enthusiastic crowd.
He said: 'We are here to support the work that the hospital does, and we are here to welcome Jeremy Corbyn.
'I want to show our allegiance to him not just for the great work that he does ever day, but what we want him to do every day in the future as the next leader of our country.'
The visit had been due to focus on Labour's policy announcement that the party would promise to enshrine in law the triple lock protection which guarantees state pensions will rise by average earnings, inflation or 2.5pc, whichever is the larger but the focus switched to the cyber attack.
Earlier he visited Lowestoft and after speaking at the hospital he went onwards to a private reception at a Norwich care home.
The candidates running in Great Yarmouth are Catherine Blaiklock (Ukip), James Joyce (Lib Dem), Brandon Lewis (Conservative), Mike Smith-Clare (Labour) Party and Harry Webb (Greens).
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