Thousands of people gather at Revolution Square to protest the attacks launched by the US and Israel on Iran.

• The US Congress voted to block US President Donald Trump from continuing the Iran war.
• Four Republicans voted with Democrats in favour of the war powers resolution.
• It was the latest setback for Trump in Congress despite his party’s slim majority.

The Republican-led US House of Representatives approved a resolution on Wednesday to block US President Donald Trump from continuing the war against Iran, reflecting growing concern among members of his party about the three-month-old conflict.

The House voted 215 to 208, as four Republicans voted with Democrats in ‌favour of the war powers resolution, which directs Trump to withdraw US troops from Iran unless Congress declares war or authorises the use of military force.

It was the latest setback for Trump in Congress despite his party’s slim majorities in both the House and Senate.

For now, the vote is largely symbolic, as legislation must pass the Senate as well as the House to become effective, and there is debate over whether war powers resolutions would be constitutional even if they are approved by Congress.

The vote, nonetheless, reflects unease among some Republicans over Trump’s handling of the conflict and marks a rare bipartisan effort to curb presidential war powers as the war has entered ⁠a fourth month.

READ | US Senate eventually passes war-powers resolution in rare Trump rebuke over Iran conflict

Three previous war powers resolutions had failed in the House by increasingly slim margins and the chamber’s Republican leaders abruptly postponed a vote on this one in May when it looked likely to pass.

The Senate advanced a separate, but similar resolution last month in a procedural vote, after seven previous attempts had failed.

Further votes on the Senate measure have not yet been scheduled.

The four House Republicans who voted for the war powers resolution were Representatives Tom Barrett of Michigan, Warren Davidson of Ohio, Brian Fitzpatrick of Pennsylvania and Thomas Massie of Kentucky.

No Democrats voted against it. Seven House members did not vote.

Trump has recently faced some opposition from members of his party in Congress, after months in which very few Republicans pushed back against his policy initiatives.

Separately on Wednesday, the House approved a procedural motion that clears the way for a vote on the Ukraine Support Act, which would provide security aid to Ukraine as it fights a Russian invasion.

The act reached the floor only after a petition reached a 218-signature threshold last month to move ahead.

Six Republicans and one independent ‌who normally ⁠votes with Republicans voted in favour of the Ukraine measure.

Republicans recently have revolted against Trump’s plans to create a “weaponisation” fund to pay his political allies who said they had been the subject of government abuse.

Republican lawmakers on Wednesday also criticised Trump’s pick of loyalist Bill Pulte - a mortgage regulator with no national security experience - to serve as acting director of national intelligence.

Democrats have called on Trump to come to Congress for authorisation to use military force in the Iran conflict, noting that the US Constitution says only the legislature, not the president, can declare war.

They warned that Trump ⁠may have pulled the country into a long conflict without setting out a clear strategy and also railed against higher prices for gasoline, food and other products since the joint US-Israeli air strikes on Iran began on 28 February.

“The passage of this WPR today signals a significant turning point: more and more Republicans are listening to their constituents who do not want another open-ended war in ⁠the Middle East,” Representative Gregory Meeks, who sponsored the war powers resolution and serves as ranking member of the Foreign Affairs Committee, said in a statement after the vote.

Democrats have made affordability a central theme of their economic message ahead of midterm elections in November that will decide whether Republicans keep control of Congress.

US producer prices posted their biggest ⁠increase in four years in April, boosted by soaring costs for goods and services since the war began.

The Trump administration insists that the war on Iran is necessary for US national security, citing an urgent need to prevent the Islamic Republic from developing a nuclear weapon.

Republican critics of the war powers resolutions call them political grandstanding by Democrats who want to weaken the US and score points against Trump.