The sport must decide next month when to take the funding
British volleyball chiefs say the sport faces "extreme challenges" because of pre-Olympic funding cuts by UK Sport.
Volleyball is one of eight sports to have had London 2012 funding slashed because of a £50m budget shortfall.
British Volleyball (BV), the game's governing body, saw its pre-Beijing budget of £4.3m slashed to £2.2m for the years up to London 2012.
And BV board member Paddy Murphy said the governing body was "bitterly disappointed" with UK Sport.
Murphy, Northern Ireland Volleyball Association president, said: "The amount allocated will set extreme challenges for us as we attempt to ensure that all six programmes (men's and women's teams in the three versions) continue to deliver on our plan to participate with credibility in the 2012 Games.
"We are bitterly disappointed that UK Sport has reduced the figure which they indicated would be available to volleyball, without explanation.
"The unique complexity of running six teams across Olympic and Paralympic disciplines means that progress depends heavily on the sport receiving more than the planning figure."
A UK Sport spokesman said some "tough decisions" had to be made, but insisted it was right to focus the limited available resources on those sports more likely to succeed in London.
UK Sport has tried to minimise the impact of the cuts by announcing that sports will be allowed to have all the cash up front rather than split annually during the four-year cycle up to 2013.
Volleyball, and the other sports which suffered cuts, have until early next month to decide how they want to receive the funding, which will be reassessed in autumn 2010.
Some sports could opt to take all the cash now in the hope their budget will be topped up in the future when the economy is stronger, with the UK currently in what is expected to be a severe recession.