Deborah Mattinson, a familiar face on the U.K. voting scene, will be in Washington D.C. to brief the Harris Walz team next week.

POLITICO learned that Deborah Mattinson will be briefing Kamala Harris on the Labour strategy for winning elections.

Mattinson, in a sign that the relationship between the two campaigns is deepening, will visit Washington D.C. the week after next. She will meet with strategists of the Harris-Walz Campaign and will share her insights on how the center-left Starmer will win the U.K. election this July.

She was the former director of strategy of the opposition leader for three years, up until the election. During that time, she stressed the importance to win back traditional Labour voters after they switched over to the Tories.

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Mattinson developed his advice for the Vice-President’s Team with the Progressive Policy Institute, a D.C. think tank run by Starmer’s former Director of Policy Claire Ainsley.

A former colleague of Mattinson’s who was granted anonymity in order to speak honestly, stated that she wanted to “put hope and change stuff to one side”, and focus ruthlessly on Harris’s appeal to swing states.

Harris is ahead of Trump in only three states out of seven identified as crucial battlegrounds for the electoral college by both campaigns.

Mattinson has been a mainstay of the U.K.’s polling scene for many years. She is best known for her focus group work under former Labour Prime Ministers Tony Blair and Gordon Brown.

Her decision comes after Starmer’s closest advisers visited Chicago to attend the Democratic National Convention, where they met with members of Vice President Biden’s campaign.

Morgan McSweeney, Labour’s chief election strategist and Downing Street Communications Director Matthew Doyle made the trip with a group of new loyal MPs.

Common challenges

This collaboration is only one part of a transatlantic network that includes think tanks, political operatives and political activists from the center-left who are shaping Washington’s policy and London’s political messaging.

Immigration, housing and the pressure of the left regarding issues like the Gaza Crisis are all common challenges that both sides of Atlantic face.

Matthew McGregor, former Labour digital director and campaign strategist for the former U.S. president Barack Obama, said to POLITICO in a recent interview that the collaboration between Labour, Democrats, has traditionally been a “one-way street” but this is changing.

McGregor stated that for the first time in nearly 25 years the Democrats think they can learn something from Labour. Starmer’s Party has returned to winning ways last seen during the era of U.K. Prime Minister Tony Blair and U.S. president Bill Clinton, who talked about a progressive, center-left, “third way.”

There is particular interest in the United States in Labour’s progress since its heavy defeat under Jeremy Corbyn in 2019. Corbyn is a far-left leader.

McGregor stated that Labour is the only Western party to have won recently, or appear likely to win from the center-left.

The speed with which Labour went from Corbyn to the current government has been fascinating for Democrats who follow British politics. It has really caught people’s interest.”

Jonathan Ashworth is the director of the Labour Together Think Tank. He was one of Labour’s top figures at the DNC in Chicago, last month. Jonathan Ashworth also served as the key strategist for Labour’s summer campaign that succeeded in ousting the Tories from power after 14 years.

He said that Democratic operatives are “interested” in the way we presented our arguments (on border security), because they plan to present the same arguments themselves.

Ashworth, a former prosecutor like Harris, said: “We kept reminding the people that he’s a tough guy who puts people behind bars and foils terrorist plots.”

“[Harris], just like Keir is relentlessly pushing the message that she is a prosecutor, who has put criminals in prison.”