The Labour leader’s visit to Lancing Parish Hall came after his party took control of Adur District Council for the first time ever – and retained its hold over Worthing.
In his first keynote speech of the general election campaign, Sir Keir said: “Whatever the polls say, I know there are countless people who haven’t decided how they’ll vote in this election.
“They still have questions about us. Has Labour changed enough? Do I trust them with my money, our borders, and our security?
“My answer is yes you can – because I have changed this party. Permanently. This has been my driving mission since day one. I was determined to change Labour so that it could serve the British people.”
Sir Keir said his changed Labour Party is ready to meet the ‘core tests’ the British people set for government.
He said: “The very foundation of any good government is economic security, border security, and national security.
“Make no mistake, if the British people give us the opportunity to serve, then this is their core test. It is always their core test.
“I haven’t worked for four years on this, just to stop now. This is the foundation, the bedrock that our manifesto and our first steps will be built upon.”
The Labour leader said he will have a ‘clear direction’ if he was to become Prime Minister.
He added: “I know those people are looking at this election, looking at me personally. So, I make this promise: I will fight for you.
“I took this Labour Party four years ago, and I changed it into the party you see today. I was criticised for some of the changes I’ve made, change is always like that.
“There are always people who say, don’t do that, don’t go so fast. But whenever I face a fork in the road, it always comes back to this: the golden thread: country first, party second.”
This was the Labour leader’s second visit to West Sussex this year. Sir Keir paid a visit to Siemens’ Three Bridges Traincare Facility in Crawley in April to find out about the company’s tailored health support to keep employees in work.