England have lost out on four World Cup points after being told they would not be allowed to reschedule their game against Zimbabwe.
Lamb has admitted defeat
The World Cup technical committee announced on Saturday morning that it would not relocate Thursday's cancelled game from Harare to South Africa.
And the England and Wales Cricket Board (ECB) confirmed that it would not make a final appeal against the decision.
The ruling is a big blow for England's chances in the competition as they prepare to begin their campaign against Holland in East London on Sunday.
They go into the Pool A game having effectively lost the fixture against Zimbabwe, who have been awarded all four points.
And they must still face defending champions Australia, Pakistan and India with just three teams set to qualify for the Super Sixes stage.
As well as missing out on the points, the ECB could face a huge claim for compensation for cancelling the match.
"After careful consideration the ECB has decided not to appeal," said ECB chief executive Tim Lamb.
"We have done everything in our power to persuade the ICC of the merits of our
"The issue has gone on long enough and it's time to move on in the interests of the cricket World Cup.
"The ECB does not agree with the decision of the technical committee and have been advised by our lawyers that the decision is legally incorrect."
England's players, backed by the ECB, refused to travel to Zimbabwe because of security concerns.
The ECB had hoped that the death-threat letter they received from an organisation called Sons and Daughters of Zimbabwe, would act as the key evidence to support their case.
But their attempts to switch the match faced serious opposition, with India's cricket chief Jagmohan Dalmiya insisting Nasser Hussain's team should be docked points.
And the technical committee ruled against them after considering a legal submission from the ECB in a seven-hour meeting in Johannesburg on Friday.
International Cricket Council chief executive Malcolm Speed said: "It's a decision that gives the committee no pleasure."
An ICC statement added: "It is unanimously decided by the technical committee that
concerns raised by the England and Wales Cricket Board (ECB) relating to new evidence over safety and security are not justified."
Zimbabwe Cricket Union chairman Peter Chingoka said: "We are delighted. This puts the matter to rest and we can now focus on the tournament."