Relations between Barack Obama and Binyamin Netanyahu neared a new low on Thursday as the White House revealed the president would not meet the Israeli prime minister when he visits Republican leaders of Congress in March.

Obama administration officials insisted the reason for the apparent diplomatic snub was “long-standing practice and principle” that US presidents should not meet foreign leaders during re-election campaigns.

“Accordingly, the president will not be meeting with Prime Minister Netanyahu because of the proximity to the Israeli election, which is just two weeks after his planned address to the US Congress,” national security council spokeswoman Bernadette Meehan said.

But the White House decision arrived as strains with the Israeli government burst into the open following an invitation from Republican House speaker John Boehner, who asked Netanyahu to discuss their shared concerns over Obama’s nuclear talks with Iran before a combined session of Congress.

“If that’s the purpose of prime minister Netanyahu’s visit two weeks before his own election, right in the midst of our negotiations, I just don’t think it’s appropriate and helpful,” said Nancy Pelosi, the Democratic House minority leader.

The brewing standoff also stood in stark contrast to a White House visit by British prime minister David Cameron, who is also running for re-election but appeared alongside Obama last week as they both warned of the dangers should Congress pass new sanctions authorisation that they insist could derail the Iran talks.

The UK elections on 7 May are eight weeks further afield than the Israeli elections, and Cameron also visited Washington two month earlier than Netanyahu’s planned trip. But the British prime minister’s official state visit to Washington was still widely interpreted as a boost to his electoral prospects back home.

Cameron also admitted to calling senators directly during his stay, urging them not to vote for proposed legislation that would authorise fresh economic sanctions on Iran if nuclear talks fail but the White House argues will cause them to fail and risk war instead.

Such open lobbying of Congress by foreign leaders over pending legislation is frowned upon in Washington. But Cameron’s talks may have helped spur Republicans to finalise the Netanyahu invitation in order to make quite the opposite argument – that a stiffer response to Iran’s threatened nuclear weapons potential is necessary as diplomatic deterrence.

The Israeli prime minister is also not the only foreign ally to have sided with Republicans over foreign policy in recent days.

Former British leader Tony Blair recently spoke to a Republican leadership retreat in Pennsylvania, urging a stronger western response to the rise of Islamic extremism.

But a pending vote in the Senate over authorising future sanctions against Iran poses a much more significant risk for the White House, particularly since a number of hawkish Democrats are also behind the legislation.

Boehner said his invitation to speak before Congress had been sent “on behalf of the bipartisan leadership of the US House of Representatives and the US Senate”. Netanyahu is expected to discuss both the threat from Iran and Islamic extremism.