For decades there has been a standing invite for the Irish prime minister to meet with the president at the White House on St. Patrick’s Day, reflecting the close bonds between the United States and Ireland.

But Enda Kenny will need the luck of the Irish if he is to pull off this year’s visit without significant criticism.

The prime minister is facing growing calls to boycott next month’s visit in protest of the temporary travel restrictions that prevent people from seven predominantly Muslim countries from entering the United States.

Some opposition politicians urged him to cancel the meeting with President Trump, while over 37,000 people have signed a petition titled “Shamrock for Trump: Not in my name.”

As tradition goes, on St. Patrick’s Day Ireland’s prime minister presents a bowl of shamrocks to the president. The White House ceremony has its roots in a small gesture made by the Irish Embassy over half a century ago. In 1952, John Hearne, Ireland’s ambassador to the United States, sent President Harry Truman a small box of the three-leafed clovers.

While the “shamrock ceremony” is largely symbolic, the meetings that surround the event are seen as hugely important for Irish-American relations and a chance for Ireland to promote its interests during one-on-one exchanges with the president.

It’s also a chance for the president to highlight the interconnectedness between the two nations and appeal to Irish immigrants and the millions of Americans with Irish heritage. According to the most recent census, there are 34.5 million Americans who claim Irish ancestry, which helps to explain why every year on March 17 the shade of green fills the streets (and sometimes rivers) of cities across the United States. New York City’s St. Patrick’s Day parade is the largest in the world.

The opposition to this year’s visit comes amid Trump’s controversial travel ban, which sparked widespread outrage and raised questions about how leaders should respond. In Britain, Prime Minister Theresa May has called the policy “wrong and divisive,” but she has also come under fire for appearing to cozy up to Trump during her recent visit to the White House. Over 1.8 million people have signed a petition saying that Britain should rescind its offer to Trump for a state visit because it would “embarrass” the queen.

Kenny has also condemned Trump’s immigration policies, telling Irish lawmakers that “the blanket ban on any country, bans on the basis of religion, are not morally acceptable and I disagree entirely with the policy.”

But he has also said that he would attend the St. Patrick’s Day ceremony, a move that has been criticized by some.

Labour Leader Brendan Howlin has said that Kenny should not go “happy clappy shamrocky” to Washington, insisting that if he does he will “present Ireland as a supine supporter of Trumpism.”

John Halligan, a government minister, also opposes the visit and said that Ireland should keep its distance from Trump, who was “close to being a fascist.”

“Unless he changes his views on issues like immigration, and his attitude to women, we should have as little as possible to do with the president,’’ said Halligan, the minister of state for training and skills.

Some opposition parties have backed the visit while stressing that it should not be a jokey affair but rather an opportunity to stand up to Trump.

Micheál Martin, the leader of the Fianna Fail party, has said the meeting should be a chance to “firmly assert” Ireland’s concerns, which includes the fate of the estimated 50,000 Irish citizens living illegally in the United States.

Indeed, some argue snubbing the annual access to the White House would be an act of self-harm, and that the best way to exert Ireland’s soft power is to attend the ceremony and meet with Trump one-on-one.

Minister for Foreign Affairs Charlie Flanagan, who visited Washington this week, said it was a “no-brainer” that Kenny should go, arguing that face time with the president was more important than “a bowl of shamrock or a photograph.”

In an editorial this week, the Irish Times newspaper said that “boycott would be the easy option, the crowd-pleaser — but wrong,” though it noted that the Irish prime minister’s actions in Washington will be scrutinized closely.

Kenny, the paper said, is “damned if he does, damned if he doesn’t.”