When Goldman Sachs boss David Solomon met with Chancellor Rachel Reeves in October, he was given a list of prepared talking points by colleagues to discuss with Britain’s top finance minister. With only one thing on his mind, he ripped up the notes and warned her: Don’t hike bank taxes in the budget.

Six weeks on, after Reeves delivered her second fiscal statement on Nov. 26 with no such tax increases, he needn’t have worried too much. Taxing Britain’s mammoth lenders could have raised £8 billion for the exchequer, a huge amount which would have gone a long way to plug the £30 billion hole Reeves needed to fill to stabilize the U.K.’s finances. But while some in the ruling Labour Party would have loved to see financial institutions taxed more, Reeves was never actually going to pull the trigger.

Publicly and privately, the lobbying efforts by banks were intense. The CEOs of Lloyds, HSBC, and NatWest all spoke out openly against the suggestion, while other leaders, such as Solomon, issued their warnings behind closed doors.

Banks couldn’t rule out a tax hike, particularly after a leaked memo revealed that former Deputy Prime Minister Angela Rayner had urged Reeves to raise the bank surcharge, an extra tax paid by banks on top of corporation tax. Certain think tanks, too, called on Reeves to go big on fat cats.

But behind closed doors, as the budget approached, City figures weren’t so concerned. Many cautioned against believing stories that a bank tax was imminent, while others said they simply hadn’t been told either way — therefore weren’t expecting a surprise in the budget.

Ultimately, they believed their lobbying was hugely successful toward a government intent on achieving growth and fearful of sending wealth out of the country.

One senior bank executive, granted anonymity to speak freely, said bank chiefs “care about two things: How easy is it to hire and fire people in the U.K, and how much tax do we pay in this country?”

For banks, their winning arguments were twofold: One, lenders pay £43.3 billion in tax every year at a 46.4 percent tax rate, higher than any other global financial center, according to data from lobby group UK Finance. Two, Reeves has been on a mission of financial deregulation since her party entered No. 10 last year. Banks argued that giving with one hand, by loosening rules, but taking away with the other, by hiking taxes, was contradictory and wouldn’t achieve the growth she so desperately wants.

“Reeves has been consistent with her messaging during her tenure,” said Benjamin Toms, bank analyst at RBC Capital Markets. “The government wants to stimulate growth, and Reeves realizes that U.K. banks are the conduit for that growth.”

Moving markets

The message appeared to get through to Reeves, even though she declined to publicly rule out hiking bank taxes.

That left rumors to intensify over the summer. Two think tanks, Positive Money and IPPR, issued reports backing a tax hike, with both recommending a windfall-style levy on bank profits. The former delivered a petition with 68,749 signatures calling for the move to the chancellor earlier this week.

The IPPR report, published at the end of August, was the most impactful, knocking £8 billion off the share prices of FTSE 100 banks the day it was published, with NatWest losing £2.5 billion alone in market cap. The Treasury worked hard to separate itself from the report, with a spokesperson saying afterward that “the chancellor has been clear that the financial services sector is at the heart of our plans to grow the economy,” but it wasn’t enough to quell rumors.

“Ultimately, negative press around banks slamming a bank tax and its effect on growth is considered more damaging to the economy than the taxes collected from the banks would bring in,” said Niklas Kammer, equity analyst at Morningstar.

Later, it emerged that Reeves “ripped into” members of the think tank after the report was published, per one person in the room at the time. She told the IPPR to think before they publish a report next time, in front of dozens of attendees at a meeting in No. 11 Downing Street in September.

While it seemed that gossip around a surcharge hike quietened down after the summer, it was immediately thrust back into the spotlight after the chancellor’s decision to rule out any income tax hikes in the budget, as Reeves began searching around for sources of income to pad her fiscal headroom.

Lobbying efforts intensified after the news on income tax broke, causing banks to panic that the move would be back on the table and warn that they’d move business elsewhere.

“We suggested in our conversation with government that if the surcharge was to go up, we might be able to move things to the EU,” added the bank executive.

After Brexit, banks have been forced to move more of their operations to the continent, buying new offices and hiring further staff, leaving greater possibilities to shift operations away from the U.K. “It’s much easier to move at the margins now than it would have been just five years ago,” they said.

But the possibility of raising taxes on banks in Britain was officially ruled out after reports circulated in the days leading up to the budget that Reeves would let them off the hook — if they praise the chancellor’s decisions.

Will Howlett, financials analyst at Quilter Cheviot, said it would be a “stretch” to see banks showering the budget with praise given the other tax rises that Reeves did pursue in the fiscal event, along with the cuts to cash ISA limits.

But Toms said it was likely “more accurate” that the government was requesting banks not criticize the budget rather than actively praise it.

For banks reeling from a huge win, staying quiet won’t be too hard.