A former Army chief has expressed dismay that legislation to protect veterans from prosecution will not feature in this Queen's Speech.
Boris Johnson has previously pledged to end the pursuit of soldiers over historical allegations in Northern Ireland, Iraq and Afghanistan.
Lord Dannatt said he was "very disappointed" that soldiers might be punished for "doing their duty".
A government source said the PM is committed to legislating on the issue.
"The PM has been clear that we need to end the unfair trials of people who served their country when no new evidence has been produced and when the accusations have already been exhaustively questioned in court," the source said.
The proposed law would have included a statutory presumption against prosecution for current or former personnel for alleged offences committed in the course of duty more than a decade ago.
Lord Dannatt, a former chief of the general staff, told the BBC's Radio 4 Today programme it was unacceptable that serving and former soldiers run the risk of prosecution for taking part in military operations.
He said: "Nobody is above the law. If soldiers have broken the law and if there is evidence to back up charges against them, then of course they must face the rigours of the law and take the consequences.
"But in the vast majority of cases, British soldiers, particularly in the campaign in Northern Ireland, got up in the morning to do their duty to keep the peace according to the rules of engagement we had, in sharp contrast to terrorists who got up in the morning whose aim was to maim and kill."
The government source told the BBC: "We are determined to make progress and legislate on the issue of legacy prosecutions.
"Our clear and overriding objective remains to provide a better way to address the past for all those affected by the Troubles."
The source said the Northern Ireland Office has consulted on the question of legacy prosecutions and the government is engaging with the main parties in Northern Ireland, MPs in Westminster and wider society across Northern Ireland to reach a broad consensus.
Six former soldiers who served in Northern Ireland during the Troubles are facing prosecution.
Not all of the charges are for murder.