Investors should prepare for the British pound to hit parity with the U.S. dollar by the end of the year or early in 2017, said at least one analyst—and should parity happen, it’ll be a first.

After last week’s surprise U.K. vote to exit the European Union trading bloc, sterling GBPUSD, +0.12% fell more than 12% against the dollar DXY, +0.03% on Friday before trimming some of its unprecedented drop late in the U.S. trading day. On Tuesday, the pound was hovering at a roughly 30-year low at $1.3342.

The details of Britain’s exit are murky, at best. Prime Minister David Cameron said he would leave the task of triggering Article 50 of the Lisbon Treaty—the untested clause that governs how countries could exit the bloc—to his successor. That raises questions of timing.

Read:Brexit’s Article 50: How 250 words could chart Britain’s future

Also read:5 ways to stop Brexit from happening

The article allows a country a maximum of two years to work out the details of an exit. But many say it could take the U.K. longer. Turmoil in the leadership of the U.K.’s two largest parties threatens to leave a political vacuum that could slow a possible resolution.

Unless these questions are answered and a clear path forward emerges, expect the pound to continue to weaken, said Shaun Osborne, chief currency strategist at Scotiabank.

“We think investors should be prepared for the risk of [pound] weakness extending quite significantly in the next few months, while uncertainty surrounding how the U.K. moves forward persists,” Osborne said.

Here are Osborne’s reasons to expect pound-dollar parity in the coming months:

The pound has a history of protracted moves

Because the Brexit vote—and the pound’s reaction—were unprecedented events, it’s difficult to predict how the currency might trade in the coming months and years. But the currency does have a history of protracted adjustments following seismic events.

The moves that followed the pound’s exit from the exchange-rate mechanism and the collapse of Lehman Brothers took months to unfold. Osborne illustrates this in the chart below:

Business investment could remain weak

The cloudy political and economic outlook could tip the U.K. into a recession as businesses delay hiring and capital spending.

Business investment fell at an annualized rate of 0.4% in the first quarter as companies awaited the outcome of the referendum. It is easy to imagine them waiting even longer now.

There is little chart support below $1.30

In the mid-1980s, the pound fell to its weakest level on record as the British economy lurched into a recession.

There appears to be little in the way of technical support to stop the currency from returning to those lows in the months ahead, Osborne said. A break below the $1.30 level—nearly where the U.K. currency is presently trading—could send the currency back to these all-time lows in the months ahead.

But not all analysts think the path to parity is unstoppable. While most market strategists see the pound weakening in the coming months, few expect such a dramatic move.

In the latest update to their forecasts, a team of currency strategists at Bank of America sees the pound ending the year at $1.30.

Economists at Capital Economics see it ending the year at $1.20.