Remain surges ahead in Brexit poll as 'In' campaign accused of treating opponents like children

The Remain campaign has been handed a major boost as support for Britain to stay in the EU surged ahead amid an increase in motivation to vote. According to the latest poll, 52% of respondents would opt to stay in the EU – a three-point increase – compared to 43% who would choose to leave if a referendum was held today. This represents a five-point decrease for Leave with undecided voters making up the remaining three points.

The ORB survey for the Telegraph also revealed that voter turnout between the two camps is narrowing. While the number of Brexit supporters who said they definitely planned to vote on 23 June remained unchanged at 70%, some 65% of Remain supporters said they are now likely to cast their vote – up four points from previously.

Writing in the newspaper, the election strategist credited with helping the Tories secure a majority in the last election, Sir Lynton Crosby noted: "The Remain campaign has also persuaded more voters of the case for staying in the EU." He added: "Greater voter contact from the Remain campaign and public perceptions of their performance could be directly related."

Despite the backlash following David Cameron's decision to spend £9.3m ($13.1m) of taxpayers' money on pro-EU leaflets, public perception is that Remain is running a better campaign (39%) than Leave (25%). To compound Eurosceptic misery, Leave supporters are more likely to change their mind than their Remain counterparts.

"This presents a challenging set of circumstances for the Leave campaign," noted Crosby. "Not only have they lost some of the advantage from more Outers being motivated to turnout that was benefiting them, but the overall proportion of the British public who support the Leave case has also fallen."

Vote Leave campaign strikes back

On 18 April, George Osborne's warning that a Brexit would cost each household the equivalent of £4,300 a year by 2030 a year dominated the news agenda. Today (19 April), the chancellor's Eurosceptic cabinet colleague is set to strike back at the tactics of "Project Fear" with a scathing attack which underlines the deep divide among Tories over the EU referendum.

"The remain campaign want us to believe that Britain is beaten and broken ... It treats people like mere children, capable of being frightened into obedience by conjuring up new bogeymen every night," Michael Gove will say. The justice secretary is expected to use a speech in London to outline his vision for a post-Brexit Britain.

Gove is also set to seize the initiative over the 200-page Treasury report, which contains estimates from the Office for Budget Responsibility on future net migration. The out campaigner insists that the government admitted in the document that immigration will rise if Britain stays in the EU. "The report from the Treasury is an official admission from the in campaign that if we vote to stay in the EU then immigration will to continue to increase by hundreds of thousands year on year," Gove will say.

"Over 250,000 people came to Britain from Europe last year. As long as we are in the EU we cannot control our borders and cannot develop an immigration policy which is both truly humane and in our long term economic interests." According to Crosby's analysis, immigration could play a key role as there is at least 11% of the electorate who are not voting Leave despite believing that it will have a positive effect on immigration in the UK.

Gove will also argue that by staying in the EU, "bosses and bureaucrats will take that as carte blanche to continue taking more power and money away from Britain ... we'll be told by Brussels to 'shut up and suck it up'".

Despite the defiant rhetoric from the justice secretary, the Leave camp was handed a double blow after the National Farmers' Union (NFU) and the Royal College of Midwives (RCM) came out in support of Britain staying in the EU. The NFU passed a resolution after a vote showed "overwhelming" support in favour of continued EU membership.

"On the balance of existing evidence available to us at present, the interests of farmers are best served by our continuing membership of the European Union," the NFU said. It was a welcome result for a delighted David Cameron, who tweeted: "The NFU is clear tonight – British farmers are better off in a reformed European Union."