It is believed the UK will make a separate direct bilateral loan to Ireland, in addition to its contribution via the European Union.
British Chancellor of the Exchequer George Osborne is likely to make an announcement about his government's commitment later today.
It is understood he will make a direct loan of £7bn (€8.17bn) available to Ireland.
Ireland is a significant export market for the UK and British banks - already bailed out by the British taxpayer - have large exposures to Irish debt.
Mr Osborne insisted that it is in Britain's national interest to commit billions of pounds to help bail out the Irish economy.
He said: 'What we have committed to do is to be partners, as shareholders in the International Monetary Fund, in an international rescue of the Irish economy.
'But we have also made a commitment to consider a bi-lateral loan that reflects the fact we are not part of the euro and don't want to be part of the euro.'
'Ireland is our very closest economic neighbour. I judged it to be in our national interest to be part of the international efforts to help the Irish.'
However, there has been opposition to the proposal from some Conservative MPs.
Douglas Carswell told the BBC: 'We shouldn't be paying to help keep Ireland in the euro.
'If we are going to pay to solve this crisis we should be helping to pay Ireland to quit the euro. Ireland's misery is only going to end when it has its own currency again.
'At a time of austerity, again we are paying vast sums to the European Union.'
IMF Managing Director Dominique Strauss-Kahn welcomed the response to the Government's request for financial assistance.
In a statement, Mr Strauss-Kahn said: 'At the request of the Irish authorities, the IMF stands ready to join this effort, including through a multi-year loan.
'An IMF team, currently in Ireland for technical talks, will now begin to hold swift discussions on an economic program with the Irish authorities, the European Commission, and the European Central Bank.'
Sweden has also indicated that it too may offer a loan to Ireland.
The Swedish prime minister said on Saturday that Sweden, which is not a member of the eurozone, could consider a bilateral loan to Ireland if one was requested.
Fredrik Reinfeldt told RTÉ News: 'There could be some bilateral help. We are waiting to hear more from the Irish Government. We feel that we are very close to Ireland and are always ready to listen and help if we can do so.'
Mr Reinfeldt said that Sweden had provided bilateral loans to both Iceland and Latvia.
Meanwhile, analysts say the Irish bailout may give short-term relief to markets, but may not prevent markets from pushing Portugal to get EU assistance too, unless a more general solution is found soon.
'In the short term this should be positive for risk appetite,' said Peter Chatwell, rate strategist at Credit Agricole CIB in London.
'It should be something Bunds see as a negative. I don't think this does anything to take Portugal and possibly Spain out of the firing line,' he said.
German Finance Minister Wolfgang Schaeuble told ZDF television yesterday his hopes were exactly the opposite.
'If we now find the right answer to the Irish problem, then the chances are great that there will be no contagion effects,' he said.
'Will it prevent contagion? In the short-term, but not in the medium term. It only calms down markets and gives the other countries some room to breathe. Particularly, Portugal is not off the hook yet,' said Carsten Brzeski, economist at ING.
If markets turn on Portugal, Spain may be next after that.
'If Portugal is forced to take a bailout then they'll turn their attention to Spain and I don't know what the government will do,' said Edro Schwartz, economist at San Pablo University in Madrid.
The underlying problem for market mistrust of debt of some euro zone countries may only be solved with a quick and detailed solution for all euro zone countries, rather than a piecemeal approach, economists said.
