Nicola Sturgeon risked a Royal faux pas today as she reached out and touched the Queen at the opening of the new Forth road crossing.

Scotland's First Minister and Her Majesty were both involved in the official opening of the Queensferry Crossing - the £1.35billion road that is Britain's tallest bridge.

Ms Sturgeon's action is a breach of Royal etiquette but no longer breaks strict protocol surrounding the Queen.

Kensington Palace this morning announced that the Duke and Duchess of Cambridge are expecting a third child - adding that the Queen and other members of the royal family were 'delighted' at the news.

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In a break with royal etiquette, First Minister Nicola Sturgeon reached out and touched the Queen's arm during a photo call after the monarch officially opened the bridge

'Delighted': The Queen and Prince Philip, who visited Queensferry this morning, are said to be thrilled at the news of Kate and William's new arrival, expected next spring

Kensington Palace this morning announced that the Duke and Duchess of Cambridge are expecting their third child - with Kate, 35, suffering from Hyperemesis Gravidarum

The SNP leader is the latest dignitary in recent years to fall foul of rules about touching the sovereign.

Michelle Obama shocked many by wrapping an arm around the Queen while on a visit to Buckingham Palace in 2009.

As recently as this year, a Canadian official broke the rules by guiding Her Majesty down some steps.

While there is no official protocol when it comes to greeting the monarch, a Buckingham Palace spokesperson has previously said they 'don't issue instructions on not touching the Queen.'

Today's event to unveil the £1.35 billion crossing after six years of construction work is taking place exactly 53 years on from the day when the monarch opened the neighbouring Forth Road Bridge.

Michelle Obama shocked many by wrapping an arm around the Queen while on a visit to Buckingham Palace in 2009 (pictured right) while a similar incident happened earlier this year when the Canadian Governor General guided the sovereign down steps

The bridge was also blessed by Church of Scotland Moderator The Right Rev Dr Derek Browning.

Philip, 96, bid farewell to his own royal jobs at Buckingham Palace at the start of August but officials stressed that he may still accompany the Queen at her events from time to time.

Speaking earlier about the ceremony, Ms Sturgeon said: 'Importantly, this celebratory event will recognise the thousands of people who have been involved in the construction of the new bridge.

'The Queensferry Crossing is a symbol of a confident, forward-looking Scotland and - as well as providing a vital transport connection for many years to come - it is a truly iconic structure and a feat of modern engineering.'

A right royal reception! Hundreds of people, mainly schoolchildren, cheered as the Queen cut the ribbon on the south side of the bridge after the royal couple met Nicola Sturgeon

The Queen was accompanied by the Duke of Edinburgh, who is making his first official appearance alongside her since retiring from solo royal engagements last month

Déja vu: The event to unveil Britain's tallest bridge is taking place exactly 53 years on from the day the Queen opened the neighbouring Forth Road Bridge, on 4 September 1954

Breaking with tradition? While there is no official protocol, a Buckingham Palace spokesperson has previously said they 'don't issue instructions on not touching the Queen'

The Duke of Edinburgh, who officially stepped down from his royal duties last month, is no doubt delighted that they will soon be welcoming a sixth great-grandchild into the family

The cutting of the ribbon today took place on the south side of the bridge after the royal couple met First Minister Nicola Sturgeon (centre) and constructors' representatives

Scottish First Minister Nicola Sturgeon speaks with officials after arriving on the Queensferry Crossing for the official opening ceremony, where she was joined by the Queen

The Queen meets construction workers who worked on the Queensferry Crossing during the official opening of the new bridge across the Firth of Forth on Monday morning

A riotous reception: Members of the Royal Regiment of Scotland march on the Queensferry Crossing as part of the official opening ceremony

Dresed in kilts, members of the Royal Regiment of Scotland march on the Queensferry Crossing which took six years and £1.35bn to construct

The formal ceremony is the high point in a week of events marking the opening of the bridge, more than a decade after plans for it were drawn up.

On Monday of last week the crossing was illuminated by a night-time light show to reflect the symbolic handover of the bridge from the contractors to the Scottish Government.

The first cars drove over the structure in the early hours of Wednesday, with many of the motorists sounding their horns and blowing whistles as they crossed.

Sightseers eager to try out the crossing when daylight came then contributed to long delays on its first day of operation.

Proud great-grandparents: Today's engagement comes amid the news that the Duke and Duchess of Cambridge are expecting a third child

Major project: The 1.7-mile Queensferry Crossing - the longest three-tower, cable-stayed bridge in the world - is the third structure connecting the Lothians and Fife

The bridge then closed again on Friday to allow 50,000 people the opportunity to take part in a 'once in a lifetime' chance to walk over the bridge during the weekend, ahead of the royal opening event. It will reopen to traffic on Thursday.

The Red Arrows marked the occasion with a flypast while a flotilla of boats travelled under the bridge.

Philip's attendance at the event sees him making his first official appearance alongside the Queen since retiring from solo royal engagements last month.

He bid farewell to his own royal jobs at Buckingham Palace at the start of August but officials stressed he may still accompany the monarch at her events from time to time.

The 1.7-mile Queensferry Crossing - the longest three-tower, cable-stayed bridge in the world - is the third structure connecting the Lothians and Fife, and sits slightly to the west of the Forth road and rail bridges.

Construction of the trio, beginning with the world-heritage-status Forth Bridge in 1883, spans three centuries.

Speaking earlier about the ceremony, Ms Sturgeon (right) said: 'Importantly, this celebratory event will recognise the thousands of people who have been involved in the construction of the new bridge'

Historic day: The formal ceremony is the high point in a week of events marking the opening of the bridge, more than a decade after plans for it were drawn up

Fanfare: The Red Arrows marked the occasion with a flypast while a flotilla of boats travelled under the bridge

The need for a new bridge for vehicles emerged 13 years ago when inspections of the Forth Road Bridge's (FRB) main cables uncovered a loss of strength.

Construction of the Queensferry Crossing began in 2011, with a variety of milestones marked along the way.

More than 10,000 people have worked on the site at some point, clocking up over 13 million hours of work.

Around 24 million vehicles are expected to use the crossing each year, reducing the strain on the older road bridge.

The new bridge has a projected life of 120 years but could last for longer than that, experts believe.

The 1.7-mile Queensferry Crossing - the longest three-tower, cable-stayed bridge in the world - is the third structure connecting the Lothians and Fife and sits slightly to the west of the Forth road and rail bridges.

Construction of the trio, beginning with the world-heritage-status Forth Bridge in 1883, spans three centuries.

The need for a new bridge for vehicles emerged 13 years ago when inspections of the Forth Road Bridge's (FRB) main cables uncovered a loss of strength.

Construction of the Queensferry Crossing began in 2011, with a variety of milestones marked along the way.

More than 10,000 people have worked on the site at some point, clocking up more than 13 million hours of work.

Around 24 million vehicles are expected to use the crossing each year, reducing the strain on the older road bridge.

The new bridge has a projected life of 120 years but could last for longer than that, experts believe.