Lobbyists behind the rightwing Tea Party group in the US will arrive in London today to spread their message of low taxes and small government at an event organised by the UK's controversial Taxpayers' Alliance.

The event, the largest of its kind in Europe, is heavily sponsored by US lobby groups that have backed the Tea Party grouping as its challenges moderate Republican party candidates in congressional elections.

Critics of the event said it established a clear link between British rightwing groups and aggressive American lobbyists who pursued low taxes, loose regulation and widespread privatisation of public services.

The Taxpayers' Alliance aggressively promotes an anti-tax, anti-state, anti-Europe agenda and many of its leading figures have close links with the Tory party and the rightwing press. Its chief executive, Matthew Elliott, will lead the "no" campaign against the adoption of the alternative vote system in next May's referendum.

Today's conference will be attended by Americans who have lobbied in the US to overturn Barack Obama's healthcare plan and maintain tax breaks for the rich. Several of the groups have close links to the billionaire brothers David and Charles Koch, prominent tormentors of the Obama administration.

US groups sponsoring the event include the Americans for Prosperity Foundation, the Cato Institute and the Heritage Foundation, which came to prominence in the 1970s as Ronald Reagan's favourite thinktank. The Kochs, whose private company owns oil rigs and pipelines in the US, founded the Americans for Prosperity Foundation and have spent tens of millions of dollars supporting the Cato Institute. They also channel funds into causes through their business empire and one Koch-owned firm, Flint Hills Resources, has donated $1m (£650,000) to the campaign against California's anti-global warning proposition being voted on in November.

The Cato Institute, which promotes its views on Fox News and other rightwing media, is one of the Tea Party's main backers.

Prominent Tory supporters are also backing the conference. Stanley Kalms, the former chairman of Dixons, is a key sponsor of the event along with investment banker Howard Flight. Flight was a Tory MP and frontbench Treasury spokesman before David Cameron became leader, while Kalms was Tory treasurer and one of its main backers.

Campaigner Richard Murphy, who wrote a report for the TUC showing how companies and wealthy individuals avoid billions of pounds of tax, said: "It's clear the Taxpayers' Alliance receives a huge amount of support from the US, where there is serious money behind the lobbying for low taxes. The conference is billed as a debate among European thinktanks, but it is a barely disguised front for the most aggressive lobby tactics championed on the other side of the Atlantic."

A spokesman for the Taxpayers' Alliance said the conference had a long history of links with US thinktanks, along with free market groups worldwide.

"It is a place for people who believe in the free market to debate ideas and how to influence events," he said.

The European Resource Bank conference, also billed as the Taxpayers' Conference and Free Market Roadshow, which will be held at various venues in the capital and includes a dinner at the Guildhall, is a spinoff from the American Resource Bank conference.

The spokesman said only that UK residents were among its 60,000 supporters. He said sponsors supported the conference with cash and help in kind, but he refused to say how much individual sponsors needed to contribute to be listed on the conference agenda.

Speakers from Norway, Italy, Switzerland and the UK will debate alongside US representatives about how to persuade governments that the answer to the recession and the financial crisis is an extension of privatisation policies and greater freedom from state controls.

The World Taxpayers Associations, which represents low tax groups in more than 60 countries, will present its audited accounts at the conference.

Murphy said: "The Taxpayers' Alliance has done a fantastic job of presenting itself as a representative of the poor downtrodden taxpayer.

"It regularly grabs slots on the BBC and other media to argue that taxpayers are hard done by. But the freedoms it wants is freedom from taxes for a tiny minority of wealthy people."

The lobby groups

The Cato Institute

A thinktank dedicated to individual liberty, limited government and free markets funded by oil majors such as Chevron, Exxon and Shell, as well as the David and Charles Koch, who made their millions from oil pipelines.

FreedomWorks

Formed after a merger between Citizens for a Sound Economy, headed by former House majority leader Dick Armey, and Empower America, co-founded by Jack Kemp, the rightwing former gridiron star whom was a prominent Reagan-era Republican.

Americans for Prosperity (AFP)

Started by oil billioniare David Koch, AFP aims to disrupt the Obama presidency and has opposed health care reform, stimulus spending, and cap-and-trade legislation. AFP has also taken a lead role in the Tea Party and its director is Art Pope, an ex-legislator who has been dubbed "The Knight of the Right".

Ronald Reagan Presidential Foundation

Created by the former president and charged by him with continuing his legacy and sharing his principles – individual liberty, economic opportunity, global democracy and national pride.

Krieble Foundation

Established in 1984 by the family of Professor Vernon Krieble, the scientist who developed Loctite glue. Committed to using its assets "to further democratic capitalism and the preserve and promote a society of free, educated, healthy and creative individuals."

Heritage Foundation

Thinktank co-founded in the early 70s by rightwing activist Paul Weyrich to counter liberal views. Became very influential in the Reagan era and was closely linked with support for anti-communist wars in central America and Afghanistan, and the "star wars" plan.

• This article was amended on 8 September 2010. The photo caption originally read A Tea Party anti-taxi protest in Atlanta. This has been corrected.