If the No side was to triumph in Lisbon 2 then the six Dublin constituencies being counted at the Citywest Hotel yesterday simply had to be carried.

In truth the count was almost over as soon as it had started, with tallies showing a massive swing to the Yes side in all six constituencies, including those that delivered some of the highest No votes last year, such as Dublin South West.

But not long after lunch, official results firmly hammered a nail in the coffin of the No campaign with huge victories in middle-class constituencies for the Yes side.

Dún Laoghaire delivered the highest Yes vote in the country in 2008 at 63.5 % and the official result for the constituency, announced shortly after 2pm, confirmed that an overwhelming majority of 81.17% of voters had endorsed the treaty there.

But it was neighbouring Dublin South that looked like it would return the highest Yes vote (81.6%) in the country yesterday afternoon.

Tallymen pointed out that some ballot boxes counted in the Rathfarnham area showed an unprecedented Yes vote of about 95%.

An early indication yesterday morning that all was lost for the No side came when tally counts in Dublin South West, which recorded the highest No vote in 2008 at 65%, showed a significant swing to the Yes side of almost 24%.

By the afternoon, the result showing support for the treaty at 59% confirmed that significant swathes of the largely working class constituency, which has unemployment rates of up to 25% in some pockets, had accepted the pro-Lisbon mantra that supporting the treaty would bring jobs and eventual economic recovery.

There were also massive increases in support for Lisbon in the Dublin North, Dublin Mid West and Dublin West constituencies from 50.6%, 39.6% and 47.9% respectively in 2008 to 72%, 61% and 68.5% this time.

Deputy Labour party leader and Dublin West TD Joan Burton said young families with mortgages were a crucial factor in the large swing to the Yes side.

"The most remarkable turnaround in Dublin West was where there were young families with mortgages, small children. They just came out in their droves to vote Yes and the consequence has been that there has basically been a swing around of 24 points in some areas," she said.

One of the most emblematic developments of the Celtic tiger, the CityWest hotel, provided the perfect setting for Yes campaigners to celebrate victory and repeat the slogan that their victory would help the country out of the ashes of its current economic nightmare.