Kempton Park has been central to the Constitution Hill story and on Saturday it will prove so once again, as the former hurdling great faces the toughest test of his fledgling Flat career in the William Hill September Stakes.

Nicky Henderson’s magnificent nine-year-old lit up Boxing Day at the Sunbury venue for three consecutive years as he recorded a hat-trick of festive wins in the Christmas Hurdle between 2022 and 2024.

However, it was also the place Champion Hurdle plans came crashing down in February 2024, when a decidedly lacklustre pre-Cheltenham gallop was headline-making news.

After wowing on his memorable Flat debut at Southwell in February, Kempton would play its part in the opening salvos of Constitution Hill’s Flat odyssey, as he made it two from two under Ryan Moore in March, and he returns to familiar territory for a race that will signpost in which direction racing’s flagship name heads next.

“The important thing is to get a run into him because that will determine where we’re going to go,” said Henderson.

“He’s got a handicap mark, but you have to have a third run to get into those handicaps that he could go for – when you’re rated over 100, you can’t get in with two runs.

“He’s got to have a run and his handicap mark is either going to go up or it’s going to go down, and that will tell us where we are according to how we perform.”

Constitution Hill needs to finish in the first three to keep alive hopes of a potential tilt at the Melbourne Cup later in the year, but a quick glance at the ratings shows just how much he has on his plate.

While the Seven Barrows superstar has only been beaten once in the 13 races he has completed under rules, he has upwards of 10lb to find with each of his six rivals and his mark of 101 puts him 16lb below the highest-rated runner, Gethin.

Henderson, then, is thoroughly aware of the task in hand.

He told talkSPORT2: “He’s had five months since his last run.

“So this race will bring him on quite a lot. It’s not going to be the biggest excuse in the world that he’s not ready. He’s ready. But he’s taking on young horses.

“We’re nine years old and he’s taking on Group One Flat horses. On ratings, we’ve got to improve over a stone.

“He’s come back looking fantastic. He’s done plenty of work. I’d like to have had a spin on the grass at some stage, but as every trainer in the country would tell you, you can’t do that at the moment.

“So we’ve got to go here and it’s on the all-weather. So we know the ground is OK, but he’s got a very hard task in front of him. But we’re up and ready for it. I say this will tell us where we belong, where he goes from here.”

While Henderson said owner Michael Buckley’s dream of the Melbourne Cup might be ambitious given countless top-class performers – including Scandinavia – have encountered issues with Australian veterinary procedures, he added: “But he’s a nine year old. He’s sound. It’s not like he’s a younger horse where their bones are still developing and there may be the scans which show something there.”

For once, Constitution Hill – who will have Billy Loughnane in the saddle for the first time – will be heading to Kempton as something of an underdog, but his legion of fans are sure to turn out in force to see if he can continue his Flat resurgence.

Simon Durrant, general manager of Kempton Park, said: “We’re all looking forward to seeing Constitution Hill back here and judging by the reaction of the public this week, so too are many of his fans.

“There’s no doubt that wherever he runs he brings that extra something and there should be a tremendous buzz around the parade ring come 2.30pm.

“Over the last few years this fixture has attracted about 1,700 racegoers and we’re expecting an above-average crowd as a result of Constitution Hill being here.

“While we know he draws a crowd wherever he goes, the William Hill September Stakes itself promises to be a strong renewal with some proven Group-level contenders and we have six other highly-competitive races on the card, too.”

Regardless of what the ratings say, bookmakers are on red alert.

Nicola McGeady of Ladbrokes said: “Constitution Hill’s popularity is at an all-time high and punters simply can’t resist backing him, regardless of the challenge in front of him.

“We’re already seeing plenty of support and if the money keeps coming, his odds could look very different by the off.”