Tory backbenchers have demanded the right to be able to veto any delivery of weapons to the Syrian rebels, amid reports of a cabinet split on the policy.
On Thursday a letter, organised by Andrew Bridgen and signed by 81 other Conservatives, was delivered to Downing Street. The North West Leicestershire MP said there were "concerns across the House and across the Conservative Party" about the idea of getting involved in the civil war.
"We really do require the prime minister to have a debate in the chamber of the Commons, and a vote, before this decision is made to arm any factions," he told HuffPost UK. "This may be another Middle East conflict with many, many sides and no end."
The letter (read in full below) states: "I believe the division and sensitivity that this issue evokes both with colleagues and the general public dictates that it is a matter that needs to be subjected to full parliamentary scrutiny and debate before we potentially become further involved in another Middle Eastern conflict."
Andrew Lansley, the leader of the House of Commons, told MPs today: "Any decision relating specifically to the arming of the Syrian National Coalition or others in Syria would be the subject of debate and an opportunity for a vote in this House."
However the signatories to the letter want to ensure any vote happens before any arms are delivered.
Basildon and Billericay MP John Baron, a member of the foreign affairs committee and one of the signatories to the letter, said he believed a "good part" of the parliamentary Conservative Party was against arming the Syrian opposition.
"We have severe reservations about arming the rebels. Whether you agree or not, many of us believe that before any policy is executed, once a deision has been made, we as parliament should have a debate and a vote on a substantive motion," he said. "That applies whether we are in recess or not."
Baron told HuffPost UK the 81 MPs felt the letter to Cameron was necessary as there was a view the policy was being "driven from No.10".
"Parliament must debate and vote on this issue before any policy of arming the rebels is executed, it's as simple as that."
It has been reported that the cabinet is split over whether to supply arms to the opposition movement. According to The Independent at least five cabinet ministers, including Nick Clegg and Ken Clarke, are opposed to the move favoured by William Hague and David Cameron.
On Thursday morning the prime minister's official spokesman insisted there was "complete agreement" within cabinet on the government's approach to the conflict.
Britain and France succeeded in lifting the EU arms embargo last month, allowing London and Paris to ship weapons to the warzone if they decide they want to.
Downing Street has insisted no decision has been taken yet. "The point of lifting the arms embargo has been to give us the flexibility to respond differently if we think that is the right thing to do, but no decision to provide lethal assistance has been taken," the prime minister's spokesman said.
Douglas Alexander has also written to William Hague to clarify whether parliament would be given a vote.
In the letter Labour's shadow foreign secretary asks: "Could you also clarify under what circumstances, as the Prime Minister implied, Parliament would be granted a vote on this issue?"
On Wednesday MPs from all parties signed a parliamentary motion calling on the government to put any decision to a Commons vote.
Tory MP Stewart Jackson, one of the signatories to the EDM, told HuffPost UK it was "not acceptable" for the government to consider ordering British forces to support the Syrian rebels with arms without parliament having a vote.
"We're trying to establish the idea the government should seek the sanction of both houses of parliament, certainly the Commons, before any direct or indirect military intervention is contemplated," he said.
Pressure to intervene in the conflict comes amid warnings President Assad is successfully pushing back the opposition.
US senator John McCain, an advocate of increased Western involvement in the civil war, said Assad was now "prevailing on the battlefield"
"Unfortunately there is a battlefield situation where Bashar Assad now has the upper hand, and its tragic," he said following a secret visit to Syria.
Letter from Andrew Bridgen, signed by 81 other Conservative MPs, in full:
Dear prime minister,
You will be aware that there is very real oncern amongst colleagues and the public about the possibility of British involvement in Syria escalating. I am writing to seek assurances that prior to any decision being taken to supply arms to the Syrian National Coalition or any other groups in Syria, a full debate and vote will be held in parliament and that in addition to this, if parliament is in recess it should be recalled to facilitate this important debate.
"I believe the division and sensitivity that this issue evokes both with colleagues and the general public dictates that it is a matter that needs to be subjected to full parliamentary scrutiny and debate before we potentially become further involved in another Middle Eastern conflict.
"I appreciate that in some matters of defence, time does not always allow for a parliamentary debate; however I do not believe this constraint applies to this potential course of action.
"I and the undersigned would be grateful if you could pledge that any decision on whether to arm the Syrian National Coalition or any other group in Syria will be subject to full parliamentary scrutiny and that you would request a recall of parliament if necessary to facilitate this."
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