King Felipe of Spain and Letizia join their daughters Princess Leonor and Infanta Sofia to meet award winners in Barcelona - after latest bombshell claims about Queen's 'affair' with her brother-in-law

Queen Letizia of Spain has put on a united front with her husband King Felipe and their daughters Princess Leonor and Infanta Sofia as they stepped out together in Barcelona.

The family appearance comes after the latest bombshell claims from Letizia's former brother-in-law Jaime Del Burgo, who earlier this year suggested they had an 'affair' after her marriage to the King.

The businessman - who dated the Queen when she was still a newsreader and was married to her sister Telma from 2012-2014 - has since claimed that he is still in contact with the royal in an interview with Argentinian newspaper Clarín.

He said: 'We have shared many years of our lives together. We have been a family. s I have always said, ours was not a relationship of lovers. The lover would be him, in any case. I mean Felipe.'

But Letizia and Felipe, who have made no public response to the claims,  showed no hint of turmoil as they attended a meeting with winners of previous editions of the Princess of Girona Foundation Awards during the events of the XV anniversary for the organisation at the Melia Lloret de Mar Hotel.

Letizia looked typically elegant in a cream sleeveless dress, featuring a daring slit and statement neckline, teamed with a pair of white heels and a matching handbag.

Appearing equally sophisticated, her husband matched the Queen's style in a cream blazer and blue shirt.

The Foundation, which is currently chaired by the King on behalf of Princess Leonor, works for young people in all areas that are critical for their future.

It seeks to become a benchmark at national level in supporting young people in their professional and personal development.

In particular, the awards ceremony recognises talented young people who are held up as role models for their good work.

Meanwhile, Princess Leonor and Infanta Sofia of Spain, who had visited a sculpting studio in Barcelona earlier in the day, appeared perfectly in sync on Tuesday.

The teenage daughters of King Felipe and Queen Letizia, 18 and 17, opted for a summery look as they made the special visit to renowned artist Jaume Plensa's studio. 

Their flawless appearance cemented their status once more as promising heirs to the throne and the future of the crown. 

Leonor has stepped up her role since turning 18 last October, and it appears the crown is looking to her for a fresh start after years of scandal plaguing the monarchy. 

The princesses were immaculately turned out in their summery outfits, and even wore matching espadrille sandals from Spanish brand Macarena Shoes. 

Eldest daughter Leonor paired a blouse with puffed sleeves with matching jeans, looking radiant as she attended gold hoops and a star-shaped piercing. 

Meanwhile Sofia opted for wide leg trousers and a blouse from Ba&sh, one of her favourite brands in a boho-style design.  

The royal visit highlighted their interest in contemporary art and culture, as they admired Plensa's acclaimed works and engaged in discussions with the artist. 

The event is part of the Princess of Girona Awards, which will be presented on July 10.  

'The Princess has a huge job to do. At 18, it's time to speak on behalf of so many like her who are looking for a space and a voice in society,' said the event's host, according to Spain's Hola Magazine. 

On Wednesday, Leonor is due to give another speech at a gala for the awards.

The family day out comes amid a turbulent time for the Spanish royal family, which began earlier this year with the publication of a bombshell book by veteran Spanish journalist Jaime Penafiel.

Letizia's former brother-in-law told the author that he met Letizia before 2000 and their alleged relationship began on a romantic trip to Venice, years before she met King Felipe.

Jaime - who is the son of the former politician Jaime Ignacio del Burgo - claims he was planning to propose to Letizia when she announced that she was dating a mysterious 'diplomat' over dinner at the Ritz hotel in Madrid in 2002.

Describing how 'serious and significant' their relationship was, the author made the unlikely claim that Jaime was 'carrying an engagement ring his his pocket' that evening.

Letizia reportedly told him that she had 'met someone who would oblige her to quit her profession', which Jaime said led him to deduce her mystery partner was Felipe. 

After the pair reportedly decided to just be friends, Jaime is said to have advised Letizia: 'Don't announce the romance, just the wedding.' 

Following their engagement announcement in 2003, Letizia - who had divorced her first husband in 1999 - allegedly asked Jaime to be a witness at their wedding.

What's more, the royal's ex-brother-in-law also made the far-fetched claim that he 'dealt' with Letizia's pre-nuptial agreement and helped to front the cost of the Queen's family's wedding outfits.

He was quoted as saying: 'When the wedding with Felipe came round, I dealt with the pre-nuptial agreement as you know, amongst other things.

'I also had to pay Letizia's family's expenses because [former King] Juan Carlos refused to pay or even go halves with me. So with the help of my friend Felipe Varela, I dressed her mum, grandmother and her sisters. And with the help of Jaime Jason, her father, grandparents and a cousin.' 

Jaime also made the incredible claim that the Queen asked to see him the night before the wedding at the exclusive El Latigazo restaurant in Madrid - where she asked him to 'never leave' her.

He sensationally claimed: 'When we met, she took hold of my hand and asked me why I had never asked her to marry me. Obviously I didn't reply. I encouraged her as best I could. The last thing she said to me before we said goodbye to each other in that restaurant was a request: 'Never leave me.''

In the book, Del Burgo described Felipe as a 'kind-hearted man' and even goes on to say that he had a 'great friendship' with the royal.  He told the author: 'I told him my problems and he told [me] his.'

The businessman even claims that Felipe 'uses [him] as a good man because he felt incapable of calming [Letizia] down' on occasions. 

Following the wedding, Jaime described how Letizia was like a 'fox in a chicken coop' as she was 'cleverer than any of them'. 

Jaime - who says the Queen nicknamed him her 'yogi pal' - claims he still had a romantic relationship with Letizia even after the wedding in 2004. He also claims he has kept 'photographs, videos, mobile phones' and text messages as evidence.

The businessman claimed that 'love was always there' in their relationship since, he claimed, they travelled to Venice together. The photograph Jaime shared on Twitter was taken during one of Letizia's pregnancies between 2005-2007.

In the book, Jaime sensationally claims that Letizia whispered that she loved him when they were lying in a hammock by a pool at her home following Princess Leonor's birth.

Jaime Penafiel goes on to write that Jaime del Burgo subsequently wrote a play called 'La Hamaca, which in English is 'The Hammock', and edited it but never distributed it. 

Following this, Jaime alleges they 'took steps forward with the goal of being free' - which involved seeking legal advice and looking at properties in the US. 

A spokesperson for the Spanish Royal Family previously told FEMAIL: 'We have no comment to make about this.'