WASHINGTON: Opposition to the US military campaign against Iran has reached its highest level in six months, with 54 per cent of Americans now opposing the military action, compared with 39pc who support it, according to a new poll released on Wednesday.

The survey was conducted by Global Strategy Group, a US public-opinion and political research firm, for Navigator Research, a public-opinion research project that regularly tracks American attitudes towards politics, the economy and major policy issues.

Opposition to the war was particularly strong among independent voters, with 66pc saying they opposed the US military campaign.

Democrats also held a narrow edge over President Donald Trump and Republicans on handling the Iran conflict, with 36pc trusting Democrats compared with 32pc for Trump and Republicans, reversing an eight-point Republican advantage in March.

The poll found that 58pc of Americans believed the war with Iran had not been worth it, including 41pc who strongly held that view. Only 34pc said the war had been worth it.

The latest figure represents an eight-point increase in the share saying the conflict had not been worth it since April, when 50pc held that view.

The findings also showed a shift in which political party Americans trust more to handle the conflict. Democrats now hold a four-point advantage over President Donald Trump and Republicans, with 36pc saying they trust Democrats more and 32pc choosing Republicans.

In March, shortly after the conflict began, Republicans and Trump held an eight-point advantage, with 39pc trusting them compared with 31pc who trusted Democrats.

Last month, US President Donald Trump’s approval rating plummeted to the lowest level of his presidency, with an overwhelming majority of Americans concerned that the war on Iran would last a long time, according to a Reuters/Ipsos poll.

Just 33pc of respondents in the four-day survey said they approve of Trump’s performance in the White House, while 64pc disapprove.

Some 80pc of Americans — including 87pc of Democrats and 71pc of Republicans — think US involvement in Iran “will go on for an extended period of time,” the poll found.

Just 16pc said the conflict would likely end in a few weeks.

The poll, conducted online, gathered responses from 1,166 US adults nationwide and had a margin of error of 3 percentage points in either direction.