Older people are being punished for the actions of others, an Irish lobby groups has said.
Fresh official advice has been issued to people over 70 or who are medically vulnerable to limit interactions to a very small network for short periods, avoid public transport where possible and shop during designated hours.
It is in response to rising numbers of cases as the Republic reverses some coronavirus lockdown measures.
Active Retirement Ireland chief executive Maureen Kavanagh said: "It's clear that the recent outbreak in cases hasn't originated from older people socialising or flouting Government guidelines.
"We do not believe in pitting one generation against another. Everyone must act together if we are to come through this.
"While we, as much as anyone, understand the need to protect our older citizens, we believe the distinct causes of the recent surge in cases must be dealt with, rather than reimposing restrictions on some of the most vulnerable in our society."
The voluntary organisation for older people has a national membership of more than 24,500.
Ms Kavanagh said: "Like everyone in Ireland at the moment, we are concerned to see the recent increase in the numbers of Covid-19 cases, and recognise the need for all sectors of society to play their part in suppressing the virus.
"However, today's announcement that older people are to limit their time spent outdoors is disrespectful to our older population."
Since the outbreak of Covid-19, older people have cocooned and followed all Government advice, she added.
"Our older people sacrificed seeing their families, they adapted to using new technologies, they followed the guidelines and remained indoors for the duration of lockdown.
"Asking them to stay indoors again and to reduce their social interaction is unfair after they have already sacrificed so much, and while our members will comply with this advice, they feel that they alone are being asked to bear the brunt of this."
Alone, another organisation which supports older people, said it wanted to protect them from Covid-19.
Chief executive Sean Moynihan said: "We feel the way to do this is to maintain social solidarity where we all follow the public health advice and collectively protect those at risk regardless of age.
"Fresh air, movement, social connection and access to medical services are essential for older people now in the winter months ahead.
"Ultimately, we stand alongside those who use our services, and we are extremely disappointed that older people may face harsh restrictions once again due to the negligence and disregard of other people across the country."