Following “very productive” conversations with the government, local council leaders agreed to move the region into the “very high” alert level, with restrictions coming into force from 00:01 on Saturday 24 October.
All four local authorities – Barnsley, Doncaster, Rotherham and Sheffield – will be covered by the restrictions.
Mr Jarvis said in a statement: “We all recognise the gravity of the situation and have taken the responsible route to ensure we save lives and livelihoods, and protect our NHS.
“More older people are contracting the virus. The number of people with Covid in our hospitals has doubled over the last 10 days, with no sign this will relent over the coming weeks. Inaction was not an option.”
Read more: What restrictions are there in tier 3 areas?
He said that local authorities called on the government to offer a “local lockdown lifeline” and that the new tier 3 restrictions will be introduced “alongside resources” to better equip the region to curb the spread of the virus and mitigate the impact of restrictions on jobs and businesses.
“While infection rates vary across South Yorkshire, collective action was the only practical choice to keep everyone in our region safe,” added Mr Jarvis.
“If restrictions are effective, individual local authorities will be able to move to lower alert levels as soon as it is safe to do so, in consultation with fellow local leaders, myself and national government.
“However, to reach that point as quickly as possible, it’s critical people in South Yorkshire follow the new restrictions as soon as they are in place. I want to thank everyone in the region for their perseverance.
“The character and grit of people in South Yorkshire will be needed in abundance to help us get through what will be an incredibly challenging period.
“Our NHS staff have worked tirelessly throughout this pandemic to keep us all safe. We owe it to them to ease the pressure ahead of the toughest winter our health service will ever face. I know people will step up and do their bit.”
The Sheffield City Region website crashed shortly after the mayor’s statement was released, but is now up and running again.
The announcement comes after tier 3 restrictions were imposed on Greater Manchester on Tuesday evening, following a breakdown in talks between local leaders and the government, who offered £22m of extra funding to support contact tracing and enforcement.
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