An Post has said mail deliveries to Galway city and county will be disrupted tomorrow because of industrial action by local members of the Communications Workers Union.
An Post said 34 staff refused to attend work yesterday, after the company rejected a union demand relating to Christmas overtime.
This weekend's action comes days ahead of a national one-day stoppage planned for Wednesday, in protest at what the union has said were breaches of an agreement by management of An Post.
Today the company said the workers' action in Galway was in breach of an agreement concluded last month over Christmas arrangements.
Charity urges postal workers not to strike
The housing charity, Focus Ireland, has appealed to management and unions at An Post to avoid a Christmas postal strike at all costs.
It said a Christmas strike could cripple fundraising drives by charities.
The Communication Workers' Union warned that the protest would be the first step in a vigorous campaign.
An Post management said the strike would prevent thousands of welfare recipients and pensioners from collecting their payments next week.
The Minister for Social Affairs, Seamus Brennan, said his department was making every effort to minimise disruption to payments.
