Boris Johnson has slammed UK opposition leader Jeremy Corbyn for appearing on Iranian state-owned TV and accused him of siding with regime hardliners rather than Britain’s allies over the Gulf crisis. Appearing in parliament for the first time since becoming Prime Minister, Mr Johnson was asked by Mr Corbyn if Gulf tension and attempts to release detained British-Iranian charity worker Nazanin Zaghari-Ratcliffe would top his agenda. “He asks about Iran," Mr Johnson said. "A right honourable gentlemen who has been paid by Press TV, who repeatedly sides with the mullahs of Tehran rather than our friends in the United States”. Mr Corbyn has defended the £20,000 payments he received for speaking on Iran's state-funded Press TV between 2009 and 2012, and said they were to “raise human rights issues”. Mr Johnson's attack was slightly undermined when it emerged that his father said his son was interested in Iran's history. The new Foreign Secretary, Dominic Raab, also appeared on Press TV in 2010 but said he waived his fee. Mr Corbyn, who condemned the seizure of a British-flagged ship last week, said the country did not need “arm-waving bluster” and that he feared Mr Johnson “overestimates himself.” Presenting an optimistic view of post-Brexit Britain, Mr Johnson began his tenure by promising MPs that the UK was at the beginning of a new "golden age” of influence and prosperity. He said he would pursue a “radical” reworking of UK immigration policy with a points-based system similar to that used in Australia. “No-one believes more strongly than me in the benefits of migration to our country but I am clear that our immigration system must change,” Mr Johnson said. His rise to the top job was assisted by his insistence that the UK would leave the EU on October 31, a message that he repeated in front of the cameras at the start of his first Cabinet meeting on Thursday. At a boisterous Westminster, on the last day before MPs break for their summer holidays, Mr Johnson urged the country to be optimistic and said there was “far too much negativity about the potential of our great country”. He said he would prefer to come to a new agreement with Brussels that would allow the UK to leave the EU with a deal in place on future relations. But Mr Johnson's insistence that Britain would leave on October 31 even without a deal in place has been criticised by MPs and business leaders, who fear it could devastate the UK economy and lead to a recession. He installed high-profile Brexit figures in pivotal jobs and stocked his new Cabinet with politicians committed to leaving regardless of whether an agreement was reached with the EU. His predecessor, Theresa May, stepped down after her withdrawal agreement with the bloc was rejected three times by Parliament. EU officials said they would not reopen negotiations into the withdrawal agreement. On Thursday, Mr Johnson told European Commission President Jean-Claude Juncker that the Northern Irish backstop must be abolished to avoid a no-deal Brexit. He told Mr Juncker that the withdrawal deal reached between Mrs May and the EU would not pass Parliament in its current form. "As you all know, we have a momentous task ahead of us, at a pivotal moment in our country's history," Mr Johnson said. "We are now committed, all of us, to leaving the European Union on October 31 or indeed earlier, no ifs, no buts. "But we are not going to wait until October 31 to get on with a fantastic new agenda for our country, and that means delivering the priorities of the people." Mr Johnson is expected to visit Northern Ireland soon for talks with the Democratic Unionist Party, which provides key support to his minority government. "Whether in London or Brussels or indeed Dublin, now is the time to work for a sensible deal," Arlene Foster, the party's leader, wrote in the <em>Belfast Telegraph.</em> "The intransigence of the last three years must be left behind."