A migrant, part of a caravan of thousands from Central America trying to reach the United States, climbs the border fence between Mexico and the United States, in Tijuana, Mexico, November 18, 2018. REUTERS/Hannah McKay TPX IMAGES OF THE DAY 

Britain's Prime Minister Theresa May and U.S. President Donald Trump walk away after holding a joint news conference at Chequers, the official country residence of the Prime Minister, near Aylesbury, Britain, July 13, 2018. REUTERS/Hannah McKay 

Athletics - IAAF World Indoor Championships 2018 - Arena Birmingham, Birmingham, Britain - March 3, 2018 France's Kevin Mayer celebrates winning Men's Heptathlon REUTERS/Hannah McKay 

A man flies a kite in Greenwich Park, London, Britain, July 25, 2018. REUTERS/Hannah McKay TPX IMAGES OF THE DAY 

Pope Francis laughs as he leaves St Mary's Pro Cathedral during his visit to Dublin, Ireland, August 25, 2018. REUTERS/Hannah McKay TPX IMAGES OF THE DAY 

Soccer Football - World Cup - Group G - Belgium vs Panama - Fisht Stadium, Sochi, Russia - June 18, 2018 Belgium's Dries Mertens in action with Panama's Jose Luis Rodriguez and Erick Davis REUTERS/Hannah McKay TPX IMAGES OF THE DAY 

Passers by react as an anti-Brexit demonstrator waves flags outside the Houses of Parliament, in London, Britain, September 10, 2018. REUTERS/Hannah McKay 

Britain's Prime Minister Theresa May prepares to speak outside 10 Downing Street after a confidence vote by Conservative Party Members of Parliament (MPs), in London, Britain December 12, 2018. REUTERS/Hannah McKay 

Soccer Football - World Cup - England fans watch Croatia v England - Flat Iron Square, London, Britain - July 11, 2018 England fans react after Croatia's first goal REUTERS/Hannah Mckay 

Rosa Julia Romero, a four-year-old migrant girl from Honduras, part of a caravan of thousands from Central America trying to reach the United States, wears her mother's shoes as she walks through a temporary shelter after heavy rainfall in Tijuana, Mexico, November 29, 2018. REUTERS/Hannah McKay TPX IMAGES OF THE DAY 

Migrants, part of a caravan of thousands traveling from Central America en route to the United States, walk along a roadside in Juchitan, Mexico, October 31, 2018. REUTERS/Hannah McKay TPX IMAGES OF THE DAY 

A migrant, traveling with a caravan of thousands from Central America en route to the United States, rests on the roadside in Tapanatepec, Mexico, October 28, 2018. REUTERS/Hannah McKay TPX IMAGES OF THE DAY 

Nancy Alejandra, an eleven-year-old migrant girl from Honduras, part of a caravan traveling from Central America en route to the United States, sleeps on the roadside as she waits to board a bus to Mexico City from Cordoba, Mexico November 5, 2018. REUTERS/Hannah McKay TPX IMAGES OF THE DAY 

Fernando Velosque, a six-year-old migrant boy from Honduras, part of a caravan of thousands from Central America trying to reach the United States, lies on the ground in front of Mexican riot police as migrants gather outside the El Chaparral port of entry of border crossing between Mexico and the United States, as seen from Tijuana, Mexico, November 22, 2018. REUTERS/Hannah McKay 

A migrant covers his face as he runs from tear gas, thrown by the U.S border patrol, near the fence between Mexico and the United States in Tijuana, Mexico, November 25, 2018. REUTERS/Hannah McKay 

Britain's Prince Harry and his wife Meghan Markle ride a horse-drawn carriage, after their wedding ceremony at St George's Chapel in Windsor, Britain, May 19, 2018. Hannah McKay: "This is my favourite image because it captures a happy and relaxed moment between the couple as they are escorted in their carriage through Windsor. The most challenging thing was knowing precisely when to press the shutter to fill the frame perfectly: a second too late or a second too early can mean you miss the moment entirely." REUTERS/Hannah McKay/Pool/File photo SEARCH "WEDDING PHOTOGRAPHS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. TPX IMAGES OF THE DAY 

Andrew Mitchell, the former Conservative Party Chief Whip, speaks to former Attorney General Dominic Grieve, as an anti-Brexit protester stands near them opposite the Houses of Parliament in London, Britain, May 10, 2018. REUTERS/Hannah McKay 

Stormzy performs at the Brit Awards at the O2 Arena in London, Britain, February 21, 2018. REUTERS/Hannah McKay 

Soccer Football - Champions League Final - Real Madrid v Liverpool - NSC Olympic Stadium, Kiev, Ukraine - May 26, 2018 Singer Dua Lipa performs before the match REUTERS/Hannah McKay 

REFILE - CORRECTING DATE Labour Party leader Jeremy Corbyn delivers his speech at the party's conference in Liverpool, Britain, September 26, 2018. REUTERS/Hannah McKay 

Nurses Josephine Warner and Hannah Hall work in the nurses station in Ward 24 at Milton Keynes University Hospital in Milton Keynes, central England, Britain, May 22, 2018. REUTERS/Hannah McKay SEARCH "MCKAY NHS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. TPX IMAGES OF THE DAY. THE IMAGES SHOULD ONLY BE USED TOGETHER WITH THE STORY - NO STAND-ALONE USES 

Inpatient Donald Ritson lies in bed in Ward 24 in Milton Keynes University Hospital in Milton Keynes, central England, Britain, May 22, 2018. "I've had so many things go wrong with my body in the last four-and-a-half years that it's just incredible that one organisation can cure so many things and treat me so kindly, efficiently, and for free. It's just astonishing,Ó said Ritson. He remembers what it was like before the state-funded NHS, when healthcare was beyond the reach of many people because they could not afford to pay doctors' fees. "I can remember my brother being ill and my parents being unable to afford to go to a doctor, so they tried to treat it themselves," he recalled. "We could never go back to that sort of system. Cradle to grave, it's not a bad idea." REUTERS/Hannah McKay SEARCH "MCKAY NHS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. TPX IMAGES OF THE DAY. THE IMAGES SHOULD ONLY BE USED TOGETHER WITH THE STORY - NO STAND-ALONE USES 

Patients participate in a physiotherapy class in the hydrotherapy pool in the Physiotherapy department at Milton Keynes University Hospital in Milton Keynes, central England, Britain, June 8, 2018. REUTERS/Hannah McKay SEARCH "MCKAY NHS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. TPX IMAGES OF THE DAY. THE IMAGES SHOULD ONLY BE USED TOGETHER WITH THE STORY - NO STAND-ALONE USES 

A surgical team prepare a patient ahead of performing an operation at Milton Keynes University Hospital in Milton Keynes, central England, Britain, May 23, 2018. REUTERS/Hannah McKay SEARCH "MCKAY NHS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. THE IMAGES SHOULD ONLY BE USED TOGETHER WITH THE STORY - NO STAND-ALONE USES 

Model Madeline Stuart, who has Down's syndrome, is prepared backstage before the Colleen Morris presentation of the Spring/Summer 2019 collection during London Fashion Week in London, Britain, September 15, 2018. REUTERS/Hannah McKay SEARCH "MODEL MADELINE" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. THE IMAGES SHOULD ONLY BE USED TOGETHER WITH THE STORY - NO STAND-ALONE USES 

A cyclist crosses Westminster Bridge in the snow, London, Britain, February 28, 2018. REUTERS/Hannah Mckay 

Miao Rong Lu, 68, swims in the sea at the Sai Wan Swimming Shed in Hong Kong, China, October 5, 2018. Rong Lu said she has been coming to the swimming shed for 30 years. REUTERS/Hannah McKay SEARCH "SAI SWIMMING" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. TPX IMAGES OF THE DAY.