President Michael D Higgins chatting with Anette McGarry from Limerick and Ethel Corduff from Tralee during a visit to University College Hospital London

BORIS Johnson was momentarily at a loss. He had bustled over to greet Sabina Higgins as she arrived to join the President at a youth event at City Hall.

But he was faced with two ladies standing together, both fair haired and smiling, and it was clear he was unsure as to which of them was Mrs Higgins.

Ooer. It might've been a bit awkward for the London Mayor if he had decided that it was the Minister for Children Frances Fitzgerald who's married to Michael D.

Luckily for Boris, Sabina took pity and extended her hand to him.

"It's me," she informed him kindly.

At least he was on safer ground with the President, who arrived a couple of minutes later, and shook hands with him and posed briefly for photographs with the iconic Tower of London as a backdrop.

Immediately tourists and locals loitering in the warm sunshine sped over with phone cameras at the ready – and it wasn't to take photos of the Irish President. They stood and chatted for a couple of minutes: "I can't tell you the excitement in my office," he told his guest. "I've got lots of Irish people and they've all been preparing freshly baked biscuits," he enthused to a bemused President.

"Have they?" he said, slightly nonplussed.

"It's unprecedented," Boris assured him cheerfully.

And it seems that despite not being the sort of chap easily able to go incognito anywhere, Boris may well have popped in and out of Ireland without being spotted. For when asked if he had any plans to travel to Ireland any time soon, he replied somewhat mysteriously, "I'm seldom away from Ireland, but not immediately".

But then Boris took his leave, and the President and Sabina attended a British-Irish youth workshop inside City Hall, where 48 young people were holding a workshop co-hosted by Gaisce/The President's Award/Duke of Edinburgh Award and the British Youth Council.

But perhaps Mr Higgins should have popped into Boris's office for a longer chinwag, as the high-flying politician may well be shaping up to replace David Cameron – if not as prime minister, given that the Tories are taking a bit of a hammering in the opinion polls right now, then as leader of the Conservatives.

Boris is having a grand time of it as London Mayor these days, busily zooming about launching multimillion life-science organisations and throwing his not-inconsiderable weight behind beleaguered city buskers.

Mr Higgins had arrived in City Hall straight from having a private lunch in 10 Downing Street. And in contrast with Boris, the current British PM is having a torrid time of it.

Yesterday, before he even broke bread with Michael D, he had received the resignation of one of his cabinet, Culture Secretary Maria Miller, and then suffered a serious roasting at his weekly session of parliamentary questions at Westminster where the insults flew – he had dismissed the Labour leader and deputy leader as "muppets", only for Ed Miliband to throw a zinger right back, declaring Cameron to be "not so much the Wolf of Wall Street, more the dunce of Downing Street".

Oh dear. Still, he made it back to 10 Downing Street with five minutes to spare before the President arrived, and even stooped to straighten up the doormat at the entrance before disappearing inside.

And he was quite enthusiastic about welcoming the President. He was "really excited" about some joint projects between the two countries," he said, adding that Ireland and Britain "are now not just neighbours, but really good friends and deep friends".

Mr Higgins was equally effusive, thanking him "for the incredible reception that I have received".

And the President was still basking in a post-banquet glow yesterday.

He had begun the second day of his state visit at the University College London Hospital (UCLH), meeting with staff and patients and lots of Irish immigrants – including a suspicious number from Galway.

Among them was Galwegian Mary Talbot, a sprightly 95-year-old who moved to England in 1938. She had worked as a nurse in the hospital and was back to see Michael D.

She even had her hair especially done for the occasion.

Not even getting stuck in a hospital lift for a few minutes dampened the President's mood.

Following his visit to the hospital, he travelled to the Royal Society to deliver a speech to a gathering of scientists. And in the afternoon, he got to tread the deep-pile carpets of a second palace in as many days.

For when the two sets of diplomatic staff were putting together the programme of events for this state visit, it transpired that there were logistical difficulties with the venue chosen for the President's meeting with deputy prime minister Nick Clegg.

So the British side rather kindly gave him the loan of Buckingham Palace for the pow-wow.

As you do.

For deep friends and the like.

Irish Independent