The big bucks sponsorship packages raise sticky questions for both parties as organizers go after major donors to raise money

Next year’s national political conventions, where Donald Trump and the winner of the Democratic primaries will be enshrined as their parties’ candidates in the 2020 presidential election, will be awash with corporate cash from donors seeking access, their marketing plans reveal.

Organizers of both the Republican and Democratic National Conventions are going after major corporate donors appealing for huge lump sums as they scramble to raise the money needed to bankroll the made-for-television events.

Fundraising materials show that both parties are hoping to lure $1m donations from corporations and wealthy individuals in exchange for access and advertising opportunities.

The big bucks sponsorship packages raise potentially sticky questions for both parties. The Republicans are effectively offering exclusive briefings with the leaders of the Trump re-election campaign in return for cash.

The Democrats may face difficult ethical issues were either Bernie Sanders or Elizabeth Warren to win the nomination. Both have shunned big money donations in the early stages of the election and Sanders has indicated he might try to do the same for the Democratic convention were he to become his party’s nominee.

The scale of the parties’ ambitions is disclosed in marketing materials provided to the Guardian by Documented, a watchdog group that investigates how corporations manipulate public policy.

The host committee for the Republican National Convention pitches its offering in the most enticing language, having set itself a total target of $70m to pay for the bonanza. It promises that “for corporate donors, the sponsorship opportunities can be incredibly valuable”. It lists a range of inducements at the RNC which will showcase Trump’s re-election bid in Charlotte, North Carolina, between 24 and 27 August.

Not only will companies have the chance to project their brands in front of up to 50,000 participants at the convention, including 15,000 members of the global media, but they can also customise packages to their corporate needs “to ensure your convention experience is both enjoyable and beneficial”.

Top-tier sponsors, making a tax-deductible donation of $1m or more, will get VIP access at the convention as well as seats at an “exclusive campaign briefing with 2020 campaign leadership”.

The Democratic National Convention, where the party’s presidential candidate will be nominated, will be held in Milwaukee, Wisconsin, from 13 to 16 July. Its host committee has also set itself a target of $70m, though that would be further supplemented by $20m from the Democratic National Convention Committee (DNCC).

Fundraising brochures put out by the host organisation Milwaukee 2020 similarly sets out a tiered approach with the top level lauded as “gold” donors contributing at least $1m each. For that largesse they are promised select advertising opportunities, VIP access and hospitality and tickets to host committee parties.

Unlike the Republicans, the DNC hosts are not dangling access to top presidential campaign figures in front of donors. However, the presence of so much corporate cash swilling around Milwaukee could yet be problematic, given the platforms of some of the party’s primary contenders.

That is especially the case for Sanders. In October his campaign told the Milwaukee Journal Sentinel that were he to become the nominee he would ban corporate donations to the convention in tune with his general desire to remove big money from US politics.

Josh Orton, policy director in the Sanders campaign, told the newspaper: “When Bernie is the nominee, everything will fundamentally change for corporate elites … A Bernie Sanders convention will be a people-powered convention.”

That would appear to conflict with the message being handed out by DNCC officials who have been telling potential donors and lobbyists that their money would be welcomed no matter who the eventual nominee is. As Politico has reported, the DNCC’s chief executive, Joe Solmonese, has taken the view that the event needs to be funded well in advance, with the use of corporate dollars, no matter who is victorious in the Democratic primaries.

“We can’t know and try to, nor can I ever suggest that we ever try to, bend this towards any one candidate’s philosophy,” Solmonese told the news site.

Though the Democrats have a more progressive stance on big money in politics than the modern Republican party, they are by no means immune to the stresses and contradictions that come from welcoming large amounts of corporate cash into their coffers.

The Open Secrets database that tracks money in US politics calculated that almost three-quarters of the $70m raised for the Philadelphia Democratic National Convention that nominated Hillary Clinton in 2016 was raised from just 17 sources.

Among those mega-donors were Facebook, the telecoms company AT&T and health insurer Independence Blue Cross which all gave $1.5m each, and American Airlines and Bank of America donating $1m each. JB Pritzker, the current Democratic governor of Illinois whose fortune comes from the Pritzker family’s ownership of the Hyatt hotel chain, gave a personal donation of $1.3m.