Liberal Democrat leader Jo Swinson has insisted the party’s manifesto shows it is not a “one-trick” anti-Brexit party.
However, Ms Swinson admitted the Lib Dems are suffering a “squeeze” in the polls.
On a campaign visit to Cambridge as the party unveiled its manifesto, Ms Swinson insisted the Lib Dems have a wide-ranging agenda.
She told the PA news agency: “We have got ambitious plans for free childcare.
“We have ambitious plans to tackle the mental health crisis.
“We have bold plans to deal with the climate emergency.
“And significant investment in schools to give children the best start in life.
“All of those things, absolutely, become much easier to do if we stop Brexit and have the benefits of remaining in the European Union.
“There is a whole Liberal Democrat agenda which is a plan for a brighter future for our country.”
Ms Swinson insisted the party would do better than the opinion polls predicted, stating: “There has obviously been a bit of a squeeze, but at this point in the 2017 election the polls weren’t a very good indicator to what actually happened in the final outcome.”
Pressed on whether her leadership style could be rubbing voters up the wrong way, Ms Swinson told PA: “I’m certainly finding that when I meet with people, I’m getting a perfectly warm and enjoyable response, having good conversations with people across the country.”
The Lib Dems are currently standing in the mid-teens in a number of opinion polls after beating Labour to hit the low twenties in some surveys a few months ago.
Ms Swinson was asked if Lib Dem claims of a potential £50 billion bonus from remaining in the EU were as untrue as they might say the Leave campaign’s referendum pledge that Brexit would deliver £350 million extra a week to the NHS was.
The Lib Dem leader said: “Well, not according to the Institute for Fiscal Studies.
“So, you don’t need to take our word for it.
“We have actually gone out and listened to the experts – I know that’s not fashionable among some Conservative Cabinet ministers.
“But we have arrived at our figures through consulting with people who know what they are talking about when it comes to the economy and we have taken a very cautious approach to looking at those figures.”
The Lib Dem leader’s comments came as the Tories were under heavy fire after rebranding one of their official Twitter accounts as a fact-checking service during Tuesday night’s televised election debate between Boris Johnson and Jeremy Corbyn.
Twitter issued a sharp rebuke that “any further attempts to mislead people” would result in “decisive corrective action” after the party’s verified press office account was temporarily renamed “factcheckUK”.
The Electoral Commission – the official elections watchdog – also issued a warning saying voters were entitled to expect “transparency and integrity” from campaigners.
Senior party figures brushed off the controversy, saying it was part of their “instant rebuttal” mechanism to challenge “nonsense” claims made by Mr Corbyn during the debate that they were preparing to sell off the NHS.
However, opposition parties accused the Tories of adopting the tactics of Donald Trump or Vladimir Putin to deliberately mislead the public.
The row coincided with an appeal from the archbishops of Canterbury and York to campaigners in the election to “honour the gift of truth”.
In a statement, Twitter said: “Twitter is committed to facilitating healthy debate throughout the UK General Election.
“We have global rules in place that prohibit behaviour that can mislead people, including those with verified accounts.
“Any further attempts to mislead people by editing verified profile information – in a manner seen during the UK election debate – will result in decisive corrective action.”
An Electoral Commission spokesman said: “While we do not have a role in regulating election campaign content, we repeat our call to all campaigners to undertake their vital role responsibly and to support campaigning transparency.”
Foreign Secretary Dominic Raab insisted it had been perfectly clear throughout that it was a Conservative Party account and that no-one among voters “gives a toss” about the cut and thrust of social media.
Liberal Democrat Brexit spokesman Tom Brake said: “This is straight out of Donald Trump or Putin’s playbook.”
Former Conservative minister David Gauke said it was “a blatant attempt to mislead people” by the Tories, and something which would not have happened under Theresa May or David Cameron.
The row comes amid repeated accusations that Mr Johnson struggles to tell the truth.
The Prime Minister was met with derisive laughter from the studio audience in Salford when he said that he considered the truth was “very important” in the General Election.
A snap YouGov poll following the debate suggested Mr Johnson came out narrowly ahead – with 51% saying they thought he had won, against 49% for Mr Corbyn.
However, on the issue of trust it was the Labour leader who came out on top, with 45% saying he was the more trustworthy, against 40% for the Prime Minister.
The Conservatives have previously faced criticism for “doctoring” a TV clip of shadow Brexit secretary Sir Keir Starmer to make it appear that he had been stumped by a question on the party’s policy on the EU.