Up to 6,000 people were on the streets of Washington DC today to support a Bill that could give citizenship rights to many of the US's undocumented Irish.
Republicans last year blocked a Bill in Congress that would have loosened controls on immigrants resident in the US for some time obtaining citizenship.
But the Democrats took control of both Congress and the Senate in last November's Mid-Term elections and today are proposing a similar Bill once again.
The party is expected to propose offering green cards and permanent resident status to all immigrants in the US who can prove residency for more than five years and have worked in the past two.
The Irish Lobby for Immigration Reform (ILIR) estimates there are around 50,000 undocumented Irish in the US.
The Bill, which would affect an estimated 11 million people, would also have a significant impact on hundreds of thousands of Central Americans - particularly Mexicans.
It is attracting heavy-weight political support with Democrats Edward Kennedy and Chuck Schumer; and Republican presidential hopeful John McCain due to speak at today's rally organised by the ILIR.
President Bush has already given a veiled signal of support for a change to the status long-term resident immigrants.
The issue is being seen by both Republicans and Democrats as a potential vote-getter in next year's presidential elections.
But there is likely to be significant opposition from the Republican right and Mr Bush has previously favoured granting temporary rights rather than a pathway to full citizenship.
In his latest State of the Union address he was coy, saying the status of immigrants needed to be resolved.
Republicans and Democrats clashed over the Bill which fell last year over the former's preference for guest-worker programmes that do not grant permanent rights.
The new Bill, again sponsored by Senator Kennedy and Senator McCain is aimed at appeasing the concerns of the Right by introducing tighter border controls and proposing guest-worker status for new immigrants while incorporating the liberal agenda of regularising the situation for illegals already living in the US.
Senator Kennedy said: "The only realistic way to re-gain control of our borders is to combine stronger enforcement with a path to citizenship for undocumented workers who are now here, and a realistic temporary worker program that includes the possibility of citizenship. "
The Bill, which has yet to be published, could be introduced on Capitol Hill as early as next week.
Irish independent MEP Marian Harkin will also raise the issue tomorrow when she meets with Democrat presidential hopeful Hilary Clinton.
Ms Harkin said the bill would be "vitally important for the millions of European citizens now living and working in America contributing to society and the economy in a valuable way".
"Many of them have families now and have settled down but still live in legal limbo," she added.
The ILIR will hold a meeting in Dublin next month.