Here are a few options for a formal title, depending on the desired emphasis:

Option 1 (Most direct and formal):

UK Culture Minister resigns from X, citing ‘abuse and misinformation’

Option 2 (Slightly more authoritative):

UK Culture Minister departs X platform over concerns regarding abuse and misinformation

Option 3 (Focusing on the act of quitting):

UK Culture Minister quits X, alleging prevalence of abuse and misinformation

Recommendation: Option 1 is the most standard format for formal news reportage in the UK.

Here are a few ways to rewrite the title in a formal tone, depending on your preferred level of conciseness:

• Ambassador Audrey Marks Rejects Claims Regarding TCN Agreement as “Total Misinformation”
• Ambassador Audrey Marks Refutes Misinformation Concerning TCN Agreement
• Ambassador Audrey Marks Issues Clarification Regarding TCN Agreement Misinformation

Recommendation: The first option is the most balanced and journalistic.

Depending on the desired nuance, here are a few ways to rewrite that title in a formal tone:

Option 1 (Most direct and formal):

Examining Disinformation in the Tourism and Political Sectors

Option 2 (Focusing on the intersection):

The Intersection of Disinformation in Travel and Political Discourse

Option 3 (Sophisticated and Academic):

Disinformation Trends: An Analysis of the Travel and Political Landscapes

Option 4 (Concise):

Analyzing Disinformation Across Travel and Politics

Recommendation: If this is for an article heading, Option 2 maintains the most professional balance while clearly identifying the subject matter.