Jobs are bountiful, luring back emigrants and drawing newcomers. Property prices are soaring. Chic restaurants are fully booked weeks in advance. RTÉ television is showcasing the top new entries to Ireland’s rich list – many of them tech tycoons , plus a Ferrari salesman and other purveyors of luxury.

Not long ago considered a hopeless case, Ireland’s economy is now roaring ahead with 5.6% GDP growth, making it the European Union’s star performer.

Brexit, changes to the global tax environment and warnings of a property bubble cast shadows but so far are not spoiling the party.

Not everyone, however, is invited.

Irish government figures published last week showed a record number of people in emergency accommodation in July – 6,024 adults and 3,867 children, up by about a quarter since the same month last year.

Almost 700 families have become homeless in Dublin so far this year, including 122 families in July, averaging four a day, according to the advocacy group Focus Ireland.

The numbers give a jolting reminder about wide inequality in a country that enjoys a reputation for social justice and progressive policies.

“It’s virtually an emergency situation,” said Tommy Gordon, who manages Wicklow Homeless Five Loaves, a drop-in centre south of Dublin. “We’re supplying tents and sleeping bags to the homeless and food to those in financial difficulty.”

About 40 people a day use the centre, up about a quarter from last year. When the Guardian visited, a dozen men and women, some hunched and weather-beaten, were lunching on curry and rice. A recently installed shower is in near-continuous use, said Gordon.

A homeless woman named Margaret Cash, 28, made headlines last month after posting pictures of six of her children sleeping on chairs at a police station in Tallaght, west Dublin.

Activists and service providers blame the crisis on spiralling rents and a crippling housing shortage, especially affordable, social housing.

“This is evidence of our broken housing system. Successive governments have stepped away from building social housing,” said Niamh Randall, a spokesperson for the Simon Communities, a housing charity.

The state had left housing to market forces which were not delivering, she said. “There is growing commodification of housing, we’re seeing more vulture funds moving in. But the private rented sector doesn’t have the supply to respond.”

An influx of high-paid workers with multinationals, especially tech firms, was adding pressure on scarce supply, said Randall.

A backlash is brewing. Using the hashtags #homes4all and #TakeBackTheCity a coalition of housing activists last month occupied a four-storey property in the heart of Dublin which has been vacant for three years.

Dozens have rallied outside while others inside have bedded down. They remained there at the weekend in defiance of a court order to leave the property last week.

“Injunction be damned: it’s better to break the law than to break the poor,” tweeted Mick Barry, a socialist member of the Dáil, Ireland’s parliament.

If and when police enforce the court order the activists will move onto another vacant property in the city centre, said Michelle Connolly, an occupier affiliated with the group Dublin Central Housing Action. “There are plenty to choose from.”

The coalition includes Brazilian Left Front, a group representing Brazilians and other foreigners who battle high rents, overcrowding, slum conditions and eviction in Dublin.

Their plight jars with the perception that Ireland is on a roll.

No one dares call it the Celtic Tiger – the nickname of a decade-long boom that ended disastrously in 2008 with a financial crash, bank bailouts and harsh austerity – but the economy, driven by domestic demand, is near full employment.

Official figures last week showed that for the first time since 2009 more Irish people this year have returned to live in Ireland than those who emigrated.

Legalisation of same-sex marriage and the lifting of an abortion ban have given Ireland a progressive sheen but homelessness taints that image.

“The idea of the boom being back is not really reflected in people’s lived experiences on the ground. Rents are increasing, wages are not,” said Connolly.

She hoped occupations will spread. “We’re doing this action to kickstart people into doing more. We’d love to see other groups start to do similar actions. We’re getting a lot of messages from around the country looking for advice.”

The activists are in touch with Acorn, a British-based renters’ rights group, and have studied San Francisco’s Anti-Eviction Mapping Project.

An alliance of trade unions, students, housing groups and leftwing political parties is due to launch a “Raise the Roof” initiative this week in advance of a rally outside the Dáil on 3 October.

Activists said finding accommodation for the homeless and dispossessed – such as a father and son recently pictured sleeping rough near a plush Dublin hotel – was a more urgent reason to mobilise than Donald Trump’s planned visit to Ireland in November, which Irish critics of the US president have vowed to oppose.

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