In his speech, Thomas-Symonds said Brexit bureaucracy was weighing down businesses and reiterated the government’s ambition to agree a final UK-EU food and drink deal by 2027.
He said the deal would boost growth, protect businesses, secure jobs and bring down food prices.
But he said Farage had “pledged to reverse our progress”.
In an interview with the Telegraph in May, external, Farage said he would tear up the UK’s Brexit treaties if he became prime minister.
He said Reform UK – which is leading in national opinion polls – would “undo all of this with legislation” if it won the next general election.
“We’d tell the EU that any agreements are no longer legally binding on the UK, because a general election has said so,” Farage told the paper.
On Wednesday, a Reform spokesman added: “Cosying up to the EU and leaving us entangled in reams of retained EU law which Kemi Badenoch failed to scrap will not resuscitate Britain’s struggling economy.”
Taking aim at Farage in his speech, Thomas-Symonds said: “Nigel Farage wants Britain to fail. His model of politics feeds on it.
“He offers the easy answers, dividing communities, stoking anger. We reject that. Emphatically.”
Labour has been stepping up its political attacks on Reform UK, which only has four MPs but did well in May’s local elections.
In May, Prime Minister Sir Keir Starmer said Reform UK’s policies would “crash the economy”, comparing Farage to former Tory PM Liz Truss.
In a BBC interview ahead of his speech on Wednesday, Thomas-Symonds was asked if Labour viewed Reform UK as the real opposition, rather than the Conservatives.
In reply, the Cabinet Office minister said: “At the moment that is the case.”
The Conservatives, he added, had “nothing to say”.
“They’re not on the pitch. So this is the position that there is in British politics at the moment.”